Stretch Wrap Film Usage and Cost Calculator (Pre-Stretch Savings)

How the calculator works

The tool follows the path film takes from the roll to the load and then to the invoice: load to wrap pattern, wrap pattern to film applied, applied film to film off the roll, and film off the roll to grams and money. You give it the load length, width, and height, the film web width, the overlap percent, and the number of top and bottom reinforcement wraps. From those it works out how the film climbs the load and how many times it goes around, which is the whole of the film usage. Then it turns that length into weight with the film density and thickness, and into cost with either a price per kg or a roll price and length. Everything after the wrap pattern is unit conversion, so the wrap pattern is where the accuracy lives.

The first thing the tool settles is the wrap pattern. The perimeter of the load is 2 x (length + width), the distance the film travels in one trip around. The vertical step per revolution is the film web width times one minus the overlap fraction, so a 20 in web at 50 percent overlap climbs 10 in each revolution. The body wraps are the load height divided by that step, rounded up, ceil of load height over step, because the film has to reach the top of the load. The total revolutions are the body wraps plus the top reinforcement wraps plus the bottom reinforcement wraps, which are the extra turns you make at the base to lock the load to the pallet and at the top to close it. The applied film, the film actually on the load, is the total revolutions times the perimeter.

The step that decides the cost is pre-stretch. The film off the roll, the film you pay for, is the applied film divided by one plus the pre-stretch over 100. Pre-stretch is an elongation percent, so 250 percent means the film is stretched to 2.5 times its original length and you divide the applied film by 3.5, while hand film at 30 percent divides by 1.3. This is the core saving in the whole tool: the same containment on the load costs far less film off the roll when the film is stretched more, because each meter pulled from the roll covers more of the pallet. That is why a machine at high pre-stretch beats hand wrapping by more than any change of gauge can.

From the film off the roll the tool works out weight and cost. The film mass per meter is the web width in meters times the thickness in meters times the density in kg per m3 times 1000, with LLDPE film at about 0.92 g per cm3, which is 920 kg per m3. The grams per pallet are the film off the roll in meters times that mass per meter. Cost per pallet then follows two independent paths that should agree: path A is grams per pallet over 1000 times the price per kg, and path B divides the roll length by the film off the roll per pallet to get the pallets per roll, then divides the roll price by the pallets per roll. If you enter a roll gross weight and a core weight, the tool also reports the real price per kg net of the cardboard core, and it multiplies the cost saved per pallet by your pallets per day and days per year for the annual cost saved. The two bar chart draws the film per pallet for the current and compared setups so the gap is visible at a glance. All of this feeds the wider work in the Packaging Engineering silo and the Supply Chain hub, where the pallet you wrap is the same pallet you build in the Cases Per Pallet Calculator and then load into a trailer.

The film per pallet model

The film on a pallet is a spiral, and the spiral is easier to think about as a set of complete turns. Each turn covers the perimeter of the load, 2 x (length + width), so on the default 48 x 40 in footprint one turn is 2 x (48 + 40), which is 176 in, about 4.47 m. The film does not go straight up, it overlaps itself as it climbs, and the overlap is what sets how many turns it takes to reach the top. With a 20 in web and 50 percent overlap the film climbs 10 in per turn, so a 60 in load needs 6 body wraps to cover the height, ceil of 60 over 10.

On top of the body wraps the tool adds the reinforcement wraps you make without climbing. The bottom wraps lock the load to the pallet stringers, and the top wraps close the load and hold the top layer down, and both add turns at the perimeter without adding height. The default of 2 top and 3 bottom wraps adds 5 turns to the 6 body wraps for 11 total revolutions, so the applied film on the load is 11 times the perimeter. Change the overlap, the web width, or the reinforcement wraps and the revolution count moves, which is why the tool asks for all of them rather than guessing a fixed film weight per pallet.

The applied film is a real length of film lying on the load, but it is not what you buy, because the film was stretched when it went on. That is the whole reason two well wrapped pallets can differ so much in cost, and it is the subject of the next section. The applied film sets the containment, how tightly the load is held, and the pre-stretch sets how much roll film that containment costs. Keeping the two ideas separate is the key to reading the tool: wrap enough turns for the containment the load needs, then choose the pre-stretch that delivers those turns with the least film off the roll.

Pre-stretch and the elongation math

Pre-stretch is the single biggest lever in stretch wrapping, and it is often misread. It is an elongation percent, the amount the film is lengthened as it is applied. A film at 250 percent pre-stretch has been drawn out to 2.5 times its starting length, so one meter off the roll becomes 3.5 m on the load. Hand film pulled to 30 percent becomes 1.3 m on the load. The applied film is the same in both cases if the wrap pattern is the same, but the film off the roll, the film you actually pay for, is the applied film divided by one plus the pre-stretch over 100.

That divisor is where the money is. On the default the applied film per pallet is the same 11 revolutions times the perimeter for both setups, but the current hand setup at 30 percent divides by 1.3 while the compared machine setup at 250 percent divides by 3.5. The result is 359 g off the roll by hand against 133 g by machine, for the same containment on the same load. Raising the pre-stretch from 30 percent to 250 percent cuts the film per pallet by about 63 percent, which is a far larger saving than shaving gauge or trimming a wrap could give you.

Pre-stretch is limited by the film and the machine, not by wish. Hand wrapping reaches maybe 20 to 50 percent, a powered pre-stretch head reaches 200 to 300 percent on ordinary film and more on films designed for it, and the film has to be able to take the draw without breaking. The practical point is to size the equipment for the pre-stretch you can reliably reach, because the film cost per pallet drops almost in proportion to one plus the pre-stretch. A machine that holds 250 percent is not a small improvement over a hand roll at 30 percent, it is a different cost structure.

Length to weight to cost

Once the tool knows the film off the roll per pallet, it turns that length into weight and then into money. The weight comes from the film mass per meter, which is the web width times the thickness times the density. Film thickness is quoted in gauge, micron, or mil, and the tool takes any of the three, using 1 mil equals 100 gauge equals 25.4 micron, so 80 gauge is 0.8 mil or 20.3 micron. LLDPE film has a density of about 0.92 g per cm3, and the tool defaults to that while letting you override it for a different resin. The mass per meter times the film off the roll gives the grams per pallet.

The cost per pallet then comes by two paths that should agree, which is a useful check on the inputs. The first path is by weight: grams per pallet over 1000, times the price per kg. On the default that is 359 g at $3 per kg, which is $1.08 per pallet for the hand setup and $0.40 for the machine setup at 133 g. The second path is by roll: the pallets per roll are the roll length divided by the film off the roll per pallet, and the cost per pallet is the roll price divided by the pallets per roll. On the default 5000 ft roll the hand setup gives 40 pallets per roll and the machine setup 108, because the machine pulls less film off the roll per pallet.

The two paths answer different questions. The price per kg path is best when you buy film by weight and want a clean cost per pallet, and it drives the annual saving. The roll path is best when you buy film by the roll and want to know how many pallets a roll wraps and how often you change rolls, which matters for labor and downtime as much as for film cost. When both the price per kg and the roll price and gross weight are consistent, the two paths land in the same place, and a gap between them usually means the roll’s advertised weight includes the core, which the next section handles.

The two cost paths and the core trap

The advertised price per kg on a stretch film roll can hide a real cost, the cardboard core, the tubo the film is wound on. The core weighs something, often 0.4 to 1.8 kg, and if a roll is sold by its gross weight then part of what you pay for is cardboard, not film. The real price per kg is the roll price divided by the net film weight, which is the gross weight minus the core weight. When you enter a roll gross weight and a core weight, the tool computes this real price per kg so you can compare rolls on the film you actually get.

The gap can be large. A roll sold at a 5 kg gross weight with a 1.8 kg core holds only 3.2 kg of film, so a roll price of $30 is a real $9.38 per kg, not the $6 per kg the gross weight implies. That is more than a third of the sticker weight lost to the core, and two rolls with the same gross weight and price can hold very different amounts of film if their cores differ. Pricing by net weight is the only way to compare film honestly, and it is the reason the tool reports the real price per kg net of the core as a separate line.

The core trap also explains disagreements between the two cost paths. If the price per kg path and the roll path give different costs per pallet, the usual cause is that the roll’s quoted weight is gross while the price per kg was quoted net, or the reverse. Reconciling them on net film weight brings the two paths together, and it stops a cheap looking roll with a heavy core from beating a better roll with a light one on paper. Always ask what the quoted weight includes before you compare a price per kg.

Gauge, micron, mil, and downgauging

Film thickness is quoted three ways and the tool takes all of them. One mil is 100 gauge and 25.4 micron, so 80 gauge equals 0.8 mil equals 20.3 micron, and 23 micron is a common metric machine film close to 90 gauge. Gauge and mil are the usual imperial units, micron the usual metric one, and mixing them is a frequent source of error, so the tool keeps each thickness with its own unit selector for the current and compared setups. Enter the thickness the supplier quotes in the unit the supplier uses and let the tool convert.

Downgauging means moving to a thinner film that still holds the load, and it saves weight and money at the same pre-stretch. A high performance film can contain a load at a lower gauge than a commodity film, because the resin and the film structure carry more load per micron. If you drop from 80 gauge to 50 gauge at the same 250 percent pre-stretch on the default load, the film per pallet falls from 133 g to 83 g and the cost from $0.40 to $0.25 per pallet, a saving of 50 g and $0.15 per pallet, about $7,500 a year at the default throughput. The wrap pattern and the pre-stretch are unchanged, only the film is thinner.

Downgauging and pre-stretch stack, but they are not the same lever. Pre-stretch cuts the length of film off the roll for a given containment, while downgauging cuts the mass per meter of that film. The largest single saving is usually the jump in pre-stretch from hand to machine, and downgauging is a second saving on top of it, taken carefully, because a film too thin for the load will fail. The test is always whether the load still arrives intact, which is set by containment force, not by gauge alone, so compare films on grams per pallet and on whether they hold, not on thickness or sticker price.

Containment force and wrap pattern

Containment force is what actually keeps a load together, the total holding force the film applies around the load, and it is set by the pre-stretch, the film, and the number of wraps, not by the gauge alone. A common rule of thumb targets a containment force near 1 percent of the load weight, so a 1000 kg load wants roughly 10 kg of containment force, measured at the load with a pull plate. Too little and the top layers shift or the load leans in transit, too much and you are spending film and can crush the product, so the aim is enough and no more.

The wrap pattern is how you deliver that force. More revolutions raise the containment force but also raise the film per pallet, so the reinforcement wraps are a deliberate choice, not a default to maximize. Bottom wraps matter most, because they tie the load to the pallet and stop the base from sliding, which is where most transit failures start, so the tool defaults to 3 bottom wraps against 2 top wraps. The overlap and web width set the body coverage, and a higher overlap lays more film on the load per height but also more film off the roll, so it trades containment for cost.

The practical method is to wrap for the load and then stop. Set the reinforcement wraps and the pre-stretch to reach the containment force the load weight needs, reinforce the bottom to lock the load to the pallet, check the top layer is held, and do not add turns beyond that. Benchmark figures help: hand wrapping often runs around 560 g per pallet, a machine at 300 percent pre-stretch around 187 g, and typical machine use falls in the 200 to 400 g range. If your film per pallet is far above those and the loads are stable, you are likely over wrapping, and if it is far below and loads are shifting, you are under wrapping.

Hand versus machine and payback

The clearest use of the tool is to compare hand wrapping against a machine, because the pre-stretch difference is where the money is. Hand rolls reach a low pre-stretch, so they pull a lot of film off the roll for a given containment, while a machine with a powered pre-stretch head reaches 200 to 300 percent and pulls far less. On the default load the gap is 359 g by hand against 133 g by machine, and $1.08 against $0.40 per pallet, which is 226 g and $0.68 saved on every pallet for the same containment.

At volume that per pallet gap adds up fast. The default runs 200 pallets a day over 250 days, so the $0.68 per pallet saving is about $33,870 a year in film alone. Run the same upgrade at 500 pallets a day over 250 days and it saves about $84,700 a year, which pays back the cost of a wrapping machine in a short time and then keeps saving. The film saving is only part of the case for a machine, which also cuts labor and gives more consistent loads, but the film saving alone is often enough to justify it.

The tool lets you build this case with your own numbers rather than a rule of thumb. Set the current setup to your hand roll and pre-stretch, set the compared setup to the machine and pre-stretch you would buy, enter your throughput, and read the annual cost saved and the pallets per roll for each. The pallets per roll also tells you how much less often the operator changes rolls, which is labor and downtime saved on top of the film. Together the annual film saving and the roll changes are the core of a machine business case.

Standards and where the numbers come from

Stretch film selection and use are covered by ASTM D4649, the standard guide for selection and use of stretch wrap films, and the holding or containment force is measured under ASTM D5459. These give the vocabulary and the test methods behind the numbers here: pre-stretch as an elongation percent, containment force as the holding force measured at the load, and the practice of matching the film and the wrap to the load. The 1 percent of load weight containment target is a widely used rule of thumb, not a fixed standard, so treat it as a starting point and confirm the force your loads need for your lanes.

The film mass here uses the LLDPE density of about 0.92 g per cm3, which is standard for stretch film resin, and the thickness conversions use 1 mil equals 100 gauge equals 25.4 micron. The benchmark film figures, about 560 g per pallet by hand and about 187 g at 300 percent pre-stretch by machine with a typical machine range of 200 to 400 g, are industry reference points for a standard pallet, useful for sanity checking your own result rather than as targets to hit exactly. Your real figures depend on the load size, the film, and the containment the load needs.

The estimate is a design and quoting tool, not a substitute for a wrap test on your own loads. The film per pallet, the cost per pallet, and the pallets per roll are exact for the formulas above, but the real film use depends on how the film is applied, the film’s actual behavior at your pre-stretch, the load’s shape and stability, and the machine’s settings, and containment force should be measured on the load rather than assumed. Use the tool to size the wrap, compare setups, and estimate the film and the saving, then confirm with a wrap test and a containment force check before you change a spec. For the pallet load you are wrapping, size it first on the Cases Per Pallet Calculator, and for the box that fills the pallet, check the Box Compression Strength Calculator and the RSC Box Blank Size Calculator.

Five worked examples

Example 1: hand versus machine (the widget opens on this)

This is the case the tool opens on, and it shows the pre-stretch saving on a standard pallet. A 48 x 40 x 60 in load with a 20 in web at 50 percent overlap, 2 top and 3 bottom wraps, 80 gauge film at $3 per kg on a 5000 ft roll, running 200 pallets a day over 250 days. The current hand setup at 30 percent pre-stretch uses 359 g and $1.08 per pallet, at 40 pallets per roll. The compared machine setup at 250 percent uses 133 g and $0.40 per pallet, at 108 pallets per roll. That saves 226 g and $0.68 per pallet, about $33,870 a year. The lesson: raising the pre-stretch from 30 percent to 250 percent cuts the film per pallet about 63 percent, for the same containment on the same load.

Example 2: metric heavy load

This case runs the same math in metric with micron film. A 120 x 100 x 150 cm load with a 50 cm web at 50 percent overlap, 2 top and 3 bottom wraps, 23 micron film at $2.50 per kg on a 1500 m roll, running 150 pallets a day over 300 days. The current hand setup at 60 percent pre-stretch uses 320 g and $0.80 per pallet, at 50 pallets per roll. The compared machine setup at 300 percent uses 128 g and $0.32 per pallet, at 124 pallets per roll. That saves 192 g and $0.48 per pallet, about $21,600 a year. The lesson: the same perimeter, step, and pre-stretch math works in metric with micron film, and the higher pre-stretch again does most of the work.

Example 3: downgauge to a high-performance film

This case holds the pre-stretch fixed and changes only the film, to isolate the gauge saving. The same default load, both setups at 250 percent pre-stretch, comparing 80 gauge against a 50 gauge high performance film. The 80 gauge film uses 133 g and $0.40 per pallet. The 50 gauge film uses 83 g and $0.25 per pallet. That saves 50 g and $0.15 per pallet, about $7,500 a year at the default throughput. The lesson: a thinner film that still contains the load saves weight and money at the same pre-stretch, so downgauging is a real second saving on top of pre-stretch, as long as the film still holds.

Example 4: the core (tubo) trap

This case shows why film should be priced by net weight, not gross. An 80 gauge machine roll wrapped at 250 percent is sold at a gross weight of 5 kg with a 1.8 kg core, for a roll price of $30. The net film weight is 5 minus 1.8, which is 3.2 kg, so the real price is about $9.38 per kg, not the $6 per kg the gross weight implies. That roll holds about 337 m of film, roughly 24 pallets. The lesson: always price film by net weight, because the cardboard core can be a third of the gross, and two rolls with the same gross weight and price can hold very different amounts of film.

Example 5: savings at scale

This case takes the default hand to machine upgrade and runs it at higher volume. The saving is the same $0.68 per pallet from Example 1, but run at 500 pallets a day over 250 days it saves about $84,700 a year in film alone. The lesson: at volume the film saving from higher pre-stretch is large enough on its own to pay back a wrapping machine quickly, before counting the labor saved and the more consistent loads a machine gives. The per pallet gap is small, but multiplied by throughput and days it becomes a capital decision.

Three expert tips

Pre-stretch is the lever, not the gauge

The film you pay for is the film off the roll, which is the applied film divided by one plus the pre-stretch, so the pre-stretch sets your cost per pallet more than anything else. Moving from hand wrapping at 30 percent to a machine at 250 percent roughly triples the film applied per meter pulled off the roll, which is why it cuts the film per pallet about 63 percent on the default, far more than shaving gauge does. Size the machine for the pre-stretch you can reliably reach, because the film cost falls almost in proportion to one plus the pre-stretch. Shave gauge second, after you have taken the pre-stretch saving.

Price film by net weight and containment, not sticker price per kg

Subtract the core weight to get the real price per kg, because the cardboard core can be 0.4 to 1.8 kg and can hide a third of the gross weight, as the core example shows at $9.38 real against $6 implied. Then remember that a cheaper film that needs more wraps or a heavier gauge to hold the load can cost more per pallet than a dearer film that holds at fewer grams. Compare two films on grams per pallet and cost per pallet, the numbers this tool reports, rather than on price per roll or price per kg alone. The film that holds your load at the fewest grams usually wins even if its sticker price is higher.

Wrap for the load, then stop

More revolutions raise the containment force but also raise the film per pallet, so match the wraps and the pre-stretch to the load weight rather than over wrapping every pallet. A common rule of thumb targets a containment force near 1 percent of the load weight, measured at the load with a pull plate, so heavier loads earn more wraps and lighter ones need fewer. Reinforce the bottom wraps to lock the load to the pallet, where most transit failures start, and check that the top layer is held. Benchmark against roughly 560 g per pallet by hand and 200 to 400 g by machine, and if you are far above that on stable loads you are likely over wrapping.

Limits of the method

This calculator gives a sound first pass at the film per pallet, the cost, and the saving, not a finished wrap spec. It builds the wrap pattern from the load, the web width, the overlap, and the reinforcement wraps, divides by one plus the pre-stretch to get the film off the roll, converts to grams by the film density and thickness, and reports the cost per pallet by both a price per kg and a roll price path, plus the real price per kg net of the core and the annual saving at your throughput. That is most of what you need to size a wrap, compare setups, and quote the film, and it assumes a standard spiral wrap with the reinforcement turns you enter.

What it does not do is predict whether a given wrap actually holds a given load. Containment force depends on the film’s real behavior at your pre-stretch, the load’s shape and stability, and the machine’s settings, and it should be measured on the load with a pull plate rather than assumed from the wrap count. The film off the roll also depends on how cleanly the machine reaches its rated pre-stretch, which varies with the film and the head, so treat the grams per pallet as an accurate planning figure and confirm it against a real roll. Use the tool to size and compare, then run a wrap test and a containment force check before you commit a spec.

Common mistakes to avoid

The first mistake is comparing films or setups on sticker price per kg instead of on grams and cost per pallet, which is what actually lands on the invoice. A cheaper film at a lower pre-stretch or a heavier gauge can cost more per pallet than a dearer film that holds at fewer grams, so compare on the per pallet numbers the tool reports. The second is ignoring the core, taking a roll’s gross weight as film and paying for cardboard, when the core can be a third of the gross and the real price per kg is well above the sticker.

A third mistake is treating pre-stretch as a small tuning knob rather than the main lever, and leaving a hand roll at 30 percent when a machine at 250 percent would cut the film per pallet by more than half. A fourth is mixing thickness units, entering a micron value where the tool expects gauge or the reverse, which throws the mass per meter off by a large factor, so keep each thickness with its own unit. A fifth is over wrapping every pallet to be safe, adding revolutions and film cost without checking the containment force the load actually needs. Compare on grams and cost per pallet, price by net weight, take the pre-stretch saving, keep the units straight, and wrap to the containment the load needs, and the film per pallet the tool gives will match what you buy.

Where this calculator fits

It suits anyone buying or specifying stretch film who wants to know what a pallet really costs to wrap and where the saving is. A packaging engineer can compare hand against machine, a commodity film against a high performance one, and one pre-stretch against another, all on grams and cost per pallet, and build the business case for a wrapping machine from the annual saving and the roll changes. A buyer or an estimator can turn a load size and a film spec straight into a cost per pallet and a real price per kg net of the core, and compare rolls on the film they actually hold. A warehouse or operations planner can check how many pallets a roll wraps and how often the operator changes it.

Because it separates the applied film from the film off the roll, it also builds intuition for where the film cost goes. You can watch the pre-stretch cut the film per pallet without touching the containment, see the core eat a third of a roll’s weight, and see a downgauge save on top of the pre-stretch. The natural neighbor is the Cases Per Pallet Calculator, because the pallet load you wrap here is the load you build there, so size the load and its footprint first, then wrap it. The Box Compression Strength Calculator and the RSC Box Blank Size Calculator handle the box that fills the pallet. The Packaging Engineering hub gathers these tools together, and the Supply Chain hub carries the tools that turn a well built, well wrapped pallet into a trailer and container plan.

Frequently asked questions

Sources, disclaimer, and editorial transparency

The relationships used here follow standard stretch wrapping practice and the ASTM guidance for film use, ASTM D4649 for selection and use of stretch wrap films and ASTM D5459 for holding or containment force. The perimeter of the load is 2 x (length + width); the vertical step per revolution is the web width times one minus the overlap fraction; the body wraps are ceil of load height over step; the total revolutions are the body wraps plus the top and bottom reinforcement wraps; and the applied film is the total revolutions times the perimeter. The film off the roll is the applied film divided by one plus the pre-stretch over 100. The film mass per meter is the web width times the thickness times the density, with LLDPE at about 0.92 g per cm3, and grams per pallet is the film off the roll times that mass per meter. Cost per pallet is grams per pallet over 1000 times the price per kg, or the roll price divided by the pallets per roll, where pallets per roll is the roll length over the film off the roll per pallet. The real price per kg net of the core is the roll price over the net film weight, which is the gross weight minus the core weight, and the annual cost saved is the cost saved per pallet times pallets per day times days per year. Thickness conversions use 1 mil equals 100 gauge equals 25.4 micron, and benchmark film use is about 560 g per pallet by hand and about 187 g at 300 percent pre-stretch by machine, with a typical machine range of 200 to 400 g. This calculator and guide are built and reviewed by the OpsCalculators team; see our Editorial Policy for how each tool is researched, built, and tested.

Results are accurate estimates for design and quoting, not a substitute for a wrap test or a packaging engineering review. The film per pallet, the cost per pallet, and the pallets per roll are exact for the formulas above, but the real film use depends on how the film is applied, the film’s actual behavior at your pre-stretch, the load’s shape and stability, and the machine’s settings, and containment force should be measured on the load with a pull plate rather than assumed from the wrap count. The benchmark figures are typical reference points and real loads vary, so confirm your own film per pallet against a real roll. Run a wrap test and a containment force check before you change a spec, and size the pallet load you are wrapping on the cases per pallet tool first. See our full Disclaimer. OpsCalculators.com is operated by MAFHH INTERNATIONAL LTD. Your inputs are processed in your browser and are never stored; see our Privacy Policy.