Scope 1 and 2 Carbon Footprint Calculator (GHG Protocol, Transparent Factors)

How the calculator works

The tool does the arithmetic a carbon inventory needs, one line at a time, and draws the Scope 1 versus Scope 2 split for you. You list your fuels on the Scope 1 side, each with a quantity, a unit, an emission factor, and a percent fossil, and you add the annual electricity in kWh on the Scope 2 side with a grid region and a grid factor. It multiplies each fuel out, multiplies the electricity by the grid factor, adds the two scopes, and divides by 1000 so the total reads in tonnes of CO2e. You read the total at the top, the Scope 1 and Scope 2 subtotals under it, the biogenic line when a blended fuel is set below 100 percent fossil, and the donut chart at the bottom that shows which scope carries the footprint.

Scope 1 is your direct combustion, the fuel you burn where you can see it: natural gas in a boiler, diesel in a generator or a truck, gasoline in a fleet, propane or LPG in a forklift, fuel oil in a furnace. For each fuel the contribution is quantity times fossil fraction times emission factor, where the factor is in kg CO2e per unit of that fuel. The tool ships the common factors and shows them on every row so nothing is hidden: natural gas 2.02 per m3 or 5.306 per therm, diesel 2.68 per L or 10.21 per gallon, gasoline 2.31 per L or 8.78 per gallon, propane or LPG 1.51 per L, 5.72 per gallon, or 2.94 per kg, and fuel oil 2.68 per L. You can take the fuel in metric or US units and edit any factor to match your own supplier or country.

Scope 2 is the electricity you buy from the grid. You did not burn the coal or gas that made it, but you caused the emissions by drawing the power, so the GHG Protocol counts it as yours. The location-based number is electricity_kWh times the grid emission factor, and that factor is the average carbon intensity of the grid you sit on. It varies enormously by country: the US average is about 0.350, the Mexico FE-SEN factor is 0.444 for 2024, and the Brazil SIN factor is about 0.0385 because the Brazilian grid runs largely on hydro. The tool fills the factor when you pick a region and lets you override it, because the right number is your own country and year.

The total footprint in tonnes is (Scope 1 kg plus Scope 2 kg) divided by 1000, and the donut shows the split. On a normal fossil-heavy grid the electricity usually dominates, so Scope 2 is the larger slice and cutting kWh or greening the supply moves the total most. On a clean hydro grid the balance flips: the grid contributes little, so Scope 1, the fuel and the fleet, becomes the larger share and the lever that matters. Reading the split before you plan is what tells you where a reduction will actually come from, which is why the chart sits under the numbers rather than being an afterthought.

Two more features round out the engine. The Scope 2 method select lets you switch from location-based to market-based, which uses electricity_kWh times (1 minus renewable_share) times the grid factor to credit any renewable electricity you bought through certificates or a green contract. And the percent fossil field on each fuel row handles blended fuels: when you set a fuel below 100 percent fossil, the tool splits out the biofuel share as biogenic carbon and reports it on a separate line, kept out of the fossil total the way the GHG Protocol requires. Both are covered in detail below, but the point is that the tool models the two things a real inventory has to get right beyond the basic multiply: renewable purchases and biogenic carbon.

What Scope 1 and Scope 2 are

The GHG Protocol organizes a company’s emissions into three scopes so that no source is double counted and every source has a home. Scope 1 is direct emissions from sources the company owns or controls, which in practice means combustion: boilers, furnaces, generators, and the vehicle fleet, plus any process emissions and refrigerant leaks. Scope 2 is indirect emissions from the generation of the electricity, steam, heat, or cooling the company buys and consumes. Scope 3 is everything else in the value chain, from purchased goods and business travel to the use of sold products, and it is usually the largest and hardest to measure. This tool covers Scope 1 and Scope 2 because they come straight off your fuel and utility bills and are where almost every company starts.

The reason Scope 1 and Scope 2 are grouped together as the first target is that they are the emissions a company can measure directly and act on directly. You know how much diesel you bought, how much gas the boiler used, and how many kWh the meter recorded, so the activity data already exists in your accounts. You also control the levers: you can run the boiler less, electrify the fleet, or buy renewable power. Scope 3 depends on suppliers and customers you do not control and on data you have to request or estimate, so it comes later. A defensible Scope 1 and Scope 2 inventory is the foundation that a target, a disclosure, or a reduction plan is built on.

Keeping the two scopes separate on the output matters because they behave differently. Scope 1 falls when you burn less fuel or switch to a cleaner fuel, and it is entirely within your operations. Scope 2 falls when you use less electricity, when the grid itself decarbonizes over the years, or when you buy renewable electricity, and part of it depends on decisions outside your walls. The split in the donut is not decoration; it tells you which of these two very different reduction paths carries more of your footprint, so you spend effort where the tonnes are.

Emission factors and where they come from

An emission factor converts an activity into emissions: so many kg of CO2e per unit of fuel or per kWh of electricity. For fuels the factor is a physical property of the fuel and how it burns, so it is stable and well documented. The tool ships the widely used defaults from the EPA GHG Emission Factors Hub 2024 for the US and DEFRA 2024 for the UK, and shows each one on the row it applies to: natural gas 2.02 kg CO2e per m3 (5.306 per therm), diesel 2.68 per L (10.21 per gallon), gasoline 2.31 per L (8.78 per gallon), propane or LPG 1.51 per L (5.72 per gallon, 2.94 per kg), and fuel oil 2.68 per L. These are combustion factors expressed as CO2e, so they fold the small methane and nitrous oxide contributions into the carbon dioxide using global warming potentials.

The factors are editable on every row for a reason. Your supplier may report a slightly different heating value, your country may publish its own national factors, and a formal regulatory inventory usually requires the official set rather than a generic default. The tool starts you on solid published numbers so you are not guessing, but it treats them as a starting point you confirm rather than a black box you trust blindly. Showing the factor next to the fuel is deliberate: a footprint is only defensible if the number that turned litres into tonnes is visible and sourced, so anyone reviewing your inventory can see exactly what you used.

The electricity factor is different in kind. It is not a property of a fuel but the average carbon intensity of a whole grid, which mixes coal, gas, nuclear, hydro, wind, and solar in proportions that change by country and by year. That is why it swings so widely and why it deserves the care the next section gives it. For fuels, take the shipped factor unless you have a better one; for electricity, always set the factor to your own grid and update it each year, because last year’s number and a neighbor’s number can both be wrong for you.

The grid factor and why it dominates

The grid emission factor is the single biggest variable in most footprints, and it is worth understanding before you trust any Scope 2 number. It ranges from about 0.04 kg CO2e per kWh on a clean hydro or nuclear grid to over 0.6 on a coal-heavy grid, a spread of more than fifteen times. Because Scope 2 is electricity_kWh times this factor, the same electricity consumption produces wildly different emissions depending on where you are. A wrong factor does not nudge the total; it can move it by an order of magnitude, which is why getting the grid factor right comes before any other refinement.

The default plant makes this concrete. With electricity fixed at 500,000 kWh, the Scope 2 is 175.00 t on the US average grid at 0.350, 222.00 t on the Mexico FE-SEN grid at 0.444, and only 19.25 t on the Brazil SIN grid at 0.0385. The total footprint follows: 218.55 tCO2e in the US case, 265.55 tCO2e in the Mexico case, and 62.80 tCO2e in the Brazil case, from the identical fuel use and the identical kWh. The Brazilian grid, running largely on hydro, makes the same 500,000 kWh emit almost nine times less than the Mexican grid. Nothing else in the inventory has that kind of leverage.

Two consequences follow. First, use your own country and year for the factor: the US EPA eGRID average, the Mexico FE-SEN factor, the Brazil SIN factor, or your national grid operator’s published intensity, and refresh it annually because grids decarbonize over time and last year’s number drifts. Second, the leverage tells you where to act. On a fossil-heavy grid Scope 2 dominates, so reducing kWh or buying renewable power moves the total most; on a very clean grid the leverage flips to Scope 1, so cutting fuel and fleet use matters more than switching electricity supplier. Read the grid factor first, then let the split it produces steer the plan.

Location-based and market-based Scope 2

The GHG Protocol Scope 2 Guidance asks companies to report Scope 2 two ways, and the tool supports both. The location-based number uses the physical grid average, electricity_kWh times the grid factor, and it shows your real exposure to the grid you actually draw from. The market-based number reflects the electricity you contracted for, so it credits any renewable power you bought through renewable energy certificates, an I-REC, or a green tariff: it is electricity_kWh times (1 minus renewable_share) times the grid factor, where renewable_share is the fraction of your electricity covered by those instruments.

The worked case shows the difference. Take the Mexico total of 265.55 tCO2e, then buy clean-energy certificates for half the electricity. The market-based Scope 2 becomes 500,000 kWh times (1 minus 0.5) times 0.444, which is 111.00 t, so the market-based total falls to 154.55 tCO2e while the location-based total stays at 265.55. Both numbers are real and both belong in the report. The location-based figure says what the grid you sit on actually emitted on your behalf; the market-based figure says what your electricity looked like after the certificates you paid for.

Reporting both together is what keeps the accounting honest. A company can look clean on paper by buying certificates while the grid it physically draws from is still dirty, and showing only the market-based number would hide that. Showing both side by side makes the reduction from renewable purchases visible without pretending the underlying grid changed. When you use the market-based method in the tool, set the percent renewable to the share genuinely covered by certificates or a contract, and keep the location-based number in view so the pair tells the full story.

Biogenic carbon and blended fuels

Some fuels are blends of a fossil part and a biofuel part, and the two are accounted differently. Biofuels are treated as biogenic carbon, which the GHG Protocol reports on a separate line and keeps out of the fossil total, because the carbon released was recently absorbed from the atmosphere by the crop rather than dug out of the ground. Brazil is the clearest case: diesel B carries a mandatory biodiesel blend, so diesel B15 is 85 percent fossil, and gasoline C carries an ethanol blend, so since August 2025 E30 gasoline is 70 percent fossil. The percent fossil field on each fuel row is how you handle this.

The math splits the fuel in two. Take 10,000 L of Brazil diesel B15 at the diesel factor of 2.68. The fossil Scope 1 is 10,000 times 0.85 times 2.68 = 22.78 tCO2e, and it goes into the fossil total. The biogenic part is 10,000 times 0.15 times 2.68 = 4.02 tCO2e, and it is reported on the biogenic line, not added to the fossil total. When you set a fuel below 100 percent fossil the tool does this automatically and shows the biogenic subtotal separately, so the fossil footprint stays clean and the biogenic carbon is still disclosed.

Getting this right matters for any inventory involving blended road fuel. If you enter blended diesel or gasoline at 100 percent fossil, you overstate the fossil footprint by the biofuel share; if you drop the biofuel entirely, you fail to disclose the biogenic carbon the protocol asks you to report. Setting the percent fossil to match the actual blend, 85 for B15 and 70 for E30 in the Brazilian case, or whatever your national mandate specifies, puts the fossil part in the total and the biogenic part on its own line, which is exactly what the standard requires.

From footprint to intensity and reduction

A total in tonnes is the start, not the end. The next step is usually carbon intensity, which divides the footprint by a measure of output such as revenue, units produced, tonnes shipped, or floor area, so you can compare years and sites on a like-for-like basis even as the business grows. A footprint that rises because you made more product is different from one that rises because you got less efficient, and only the intensity separates them. A dedicated Carbon Intensity calculator will handle that normalization; here the job is to produce the clean, well-sourced total that feeds it.

The split in this tool already points to where a reduction comes from. If Scope 2 is the larger slice, the levers are using less electricity, improving equipment efficiency, and buying renewable power, and the market-based method lets you show the effect of the last one. If Scope 1 is the larger slice, the levers are burning less fuel, switching to a cleaner fuel, and electrifying the fleet or the process, after which those loads move into Scope 2 where a clean grid or renewable purchase can finish the job. Reading which scope dominates before you plan is what keeps effort on the tonnes that are actually there rather than the ones that are easy to talk about.

For deeper work on each scope, this hub will grow dedicated tools. Electricity CO2e will take a single electricity bill and a grid factor and return the Scope 2 for that meter in more detail, useful when you have many sites on different grids. Fuel Combustion CO2e will do the same for a single fuel with a wider factor library and unit handling. Carbon Intensity will normalize the total you build here against your chosen output. Those three are planned tools in this silo and are named here so you know the workflow they will complete; for now this calculator produces the combined Scope 1 and Scope 2 total they build on.

Preparing activity data for an inventory

The footprint is only as good as the activity data behind it, so a little care with the inputs pays off. Pull the fuel quantities from your purchase records or meter readings for a defined period, usually a full year, and the electricity from your utility bills for the same period, so the two scopes cover the same span. Use consistent units: if you record diesel in litres, keep the factor in kg CO2e per litre, and if you record it in gallons, switch the unit and the factor together. The tool takes either metric or US units, but the quantity and the factor on a row must be in the same unit or the row will be off by the conversion.

Match each factor to the fuel and the region it applies to. The shipped EPA and DEFRA factors are sound defaults, but if your country publishes national factors, or if your supplier reports a specific heating value, use those and note the source. For electricity, set the grid factor to your own grid and year rather than accepting a default that was picked for another country. And for any blended road fuel, set the percent fossil to the actual blend so the biogenic share is split out. Keeping the factors visible and sourced is what makes the inventory defensible when someone reviews it.

Treat the result as a management estimate until it is validated for disclosure. This tool follows the GHG Protocol Corporate Accounting and Reporting Standard, the Scope 2 Guidance, and ISO 14064-1, and it uses published EPA, DEFRA, FE-SEN, and SIN factors, but a free calculator cannot know every detail of your operations or the exact requirements of a given regulation. A formal regulatory inventory, such as the Mexico RENE, which uses SEMARNAT energy-basis factors and has a reporting threshold of 25,000 tCO2e, should use the official national factors rather than generic defaults. Use this tool to build the estimate, understand the drivers, and plan reductions, and have a qualified analyst confirm the numbers before you report them externally.

Five worked examples

Example 1: the default plant, per fuel

This one shows the whole panel on one plant so the numbers are transparent. Scope 1 is four fuels: natural gas 10,000 m3 at 2.02 is 20.20 t, diesel 5,000 L at 2.68 is 13.40 t, gasoline 3,000 L at 2.31 is 6.93 t, and LPG 2,000 L at 1.51 is 3.02 t, which add to a Scope 1 of 43.55 tCO2e. The electricity is 500,000 kWh, and on the US average grid at 0.350 the Scope 2 is 175.00 t. The total is 43.55 plus 175.00, or 218.55 tCO2e, split about 20 percent Scope 1 and 80 percent Scope 2. The lesson is that on a normal grid the purchased electricity usually dominates a footprint, so the donut leans heavily to Scope 2 and that is where the first reduction effort belongs.

Example 2: the same plant on three grids

This case keeps the fuel and the kWh fixed and changes only the grid, to show how much the grid factor decides. With electricity at 500,000 kWh, the total is 218.55 tCO2e on the US grid at 0.350, 265.55 tCO2e on the Mexico grid at 0.444, and 62.80 tCO2e on the Brazil grid at 0.0385. The Scope 1 of 43.55 t never changes because the fuel never changes; all the movement is in Scope 2, which is 175.00 t, 222.00 t, and 19.25 t respectively. The lesson is that the grid factor is the single biggest lever in Scope 2, and a clean hydro grid like Brazil makes the same electricity emit almost nine times less than the Mexican grid, so the total for identical operations depends first on where you plug in.

Example 3: a US-unit facility

This case runs the tool in US units to show the same math holds. Natural gas 10,000 therm at 5.306 is 53.06 t, backup diesel 500 gallons at 10.21 is 5.105 t, propane forklifts 800 gallons at 5.72 is 4.576 t, a gasoline fleet 2,000 gallons at 8.78 is 17.56 t, and a diesel fleet 1,500 gallons at 10.21 is 15.315 t, which give a Scope 1 of 95.616 tCO2e. Electricity 1,200,000 kWh at 0.350 is a Scope 2 of 420.00 t, for a total of 515.616 tCO2e, split about 18.5 percent Scope 1 and 81.5 percent Scope 2. The lesson is that the tool takes US units or metric and the arithmetic is identical either way, as long as the quantity and the factor on each row share the same unit.

Example 4: market-based Scope 2

This case shows what buying renewable electricity does to the report. Start from the Mexico total of 265.55 tCO2e, which is a location-based Scope 2 of 222.00 t on the FE-SEN grid, then buy clean-energy certificates for half the electricity. The market-based Scope 2 is 500,000 kWh times (1 minus 0.5) times 0.444, which is 111.00 t, so the market-based total falls to 154.55 tCO2e. The location-based total stays at 265.55, because the physical grid did not change. The lesson is that the market-based method credits the renewable purchases you actually made, the location-based method shows your real grid exposure, and the GHG Protocol asks you to report both so the certificates do not hide a dirty grid.

Example 5: biogenic carbon in a blended fuel

This case shows how a blended fuel is split. Take 10,000 L of Brazil diesel B15, which is 85 percent fossil, at the diesel factor of 2.68. The fossil Scope 1 is 10,000 times 0.85 times 2.68 = 22.78 tCO2e, which goes into the fossil total. The biogenic part is 10,000 times 0.15 times 2.68 = 4.02 tCO2e, and it is reported on a separate line, not added to the fossil total. The lesson is that for blended diesel and gasoline you set the percent fossil, 85 for B15 or 70 for E30 gasoline C, so the biofuel share is counted as biogenic carbon and disclosed on its own line the way the GHG Protocol requires, keeping the fossil footprint accurate.

Three expert tips

Get the grid factor right before anything else

Scope 2 is usually the largest part of a footprint on a fossil-heavy grid, and the grid factor swings from about 0.04 on a clean hydro grid to over 0.6 on a coal grid, so a wrong factor can move the total by an order of magnitude. Use your own country and year: the US EPA eGRID average, the Mexico FE-SEN, or the Brazil SIN, and update it each year because grids decarbonize over time. The three-grid example makes the point, with the same 500,000 kWh emitting 175.00 t, 222.00 t, or 19.25 t depending on the grid. On a very clean grid the leverage flips to Scope 1, so cutting fuel and fleet use matters more than switching electricity supplier. Set the grid factor first, then read the split it produces before you decide where to reduce.

Report location-based and market-based side by side

Location-based Scope 2 uses the physical grid average and shows your real exposure; market-based reflects the clean electricity you actually bought through certificates or contracts. The GHG Protocol Scope 2 Guidance asks for both, because a company can look clean on paper through certificates while the grid it draws from is still dirty. The Mexico example shows the gap: a location-based total of 265.55 tCO2e against a market-based total of 154.55 after buying certificates for half the electricity. Show both numbers so the reduction from renewable purchases is honest and visible, and set the percent renewable in the tool to the share genuinely covered by an instrument, not to what you hope to buy.

Keep the factors editable and cite them

A footprint is only defensible if the factors are shown, sourced, and matched to your fuels and region. Use the EPA or DEFRA defaults as a starting point, but for a formal inventory such as the Mexico RENE switch to the official national factors, which for RENE means the SEMARNAT energy-basis set rather than a generic default. For Brazil, split the biofuel share of blended diesel and gasoline into biogenic carbon using the percent fossil field. Treat any free calculator, including this one, as a management estimate until a qualified analyst validates the numbers for disclosure. The factors are visible on every row here for exactly this reason: so the number that turned your fuel and kWh into tonnes can be checked by anyone reviewing the inventory.

Common mistakes to avoid

The first mistake is using the wrong grid factor. Because Scope 2 is kWh times the factor and the factor varies more than fifteen times between grids, a default picked for another country can move your total by an order of magnitude; set the factor to your own grid and year. The second is mismatched units on a fuel row. The quantity and the factor must be in the same unit, so diesel in gallons needs the per-gallon factor of 10.21, not the per-litre factor of 2.68, or the row is off by the litre-to-gallon conversion.

A third mistake is entering blended road fuel at 100 percent fossil, which overstates the fossil footprint by the biofuel share; set the percent fossil to the actual blend so the biogenic part splits out. A fourth is reporting only the market-based Scope 2 and hiding the location-based number, which lets certificates mask a dirty grid; report both. A fifth is treating the estimate as a formal inventory: this tool follows the GHG Protocol and uses published factors, but a regulatory filing such as the Mexico RENE needs the official national factors and a qualified reviewer. Set the right grid factor, match the units, split the biofuel, report both Scope 2 numbers, and validate before you disclose, and the footprint will hold up.

Where this calculator fits

It suits anyone who needs a company carbon number and has the fuel and electricity data to build it. A sustainability or ESG lead can enter the year’s fuel and kWh, read the total and the Scope 1 versus Scope 2 split, report both location-based and market-based Scope 2, and produce a defensible estimate to base a target on. An operations or facilities manager can see which scope carries the footprint and aim the reduction plan at the tonnes that are actually there, whether that is fuel and fleet on a clean grid or electricity on a dirty one. A finance or compliance analyst can use the transparent, sourced factors to prepare an estimate for review before a formal inventory is filed.

This is the flagship of the ESG and Compliance set and the starting point for the other tools in it. The Electricity CO2e calculator will take a single electricity bill and a grid factor for a detailed Scope 2 on one meter, the Fuel Combustion CO2e calculator will do the same for a single fuel with a wider factor library, and the Carbon Intensity calculator will normalize the total you build here against revenue, units, or floor area so you can compare years and sites. Safety Incident Rates and Waste Diversion Rate round out the compliance side of the silo. Those tools are planned and named here for reference; they are not yet live, so treat them as the workflow this hub will grow into. The ESG and Compliance hub gathers them as they go live, and for the kWh side of Scope 2 the Energy Management hub covers electricity use and efficiency in more depth.

Frequently asked questions

Sources, disclaimer, and editorial transparency

The relationships used here are standard greenhouse gas accounting under the GHG Protocol Corporate Accounting and Reporting Standard and its Scope 2 Guidance, with ISO 14064-1. Scope 1 = sum over fuels of (quantity times fossil_fraction times emission_factor) in kg CO2e; Scope 2 location-based = electricity_kWh times grid_factor; Scope 2 market-based = electricity_kWh times (1 minus renewable_share) times grid_factor; and the total in tonnes = (Scope 1 kg plus Scope 2 kg) divided by 1000. Biogenic carbon from the biofuel share of a blended fuel is reported separately and kept out of the fossil total. The fuel factors are the EPA GHG Emission Factors Hub 2024 and DEFRA 2024 defaults shown on each row: natural gas 2.02 per m3 (5.306 per therm), diesel 2.68 per L (10.21 per gallon), gasoline 2.31 per L (8.78 per gallon), propane or LPG 1.51 per L (5.72 per gallon, 2.94 per kg), and fuel oil 2.68 per L. The grid factors are the US EPA eGRID average about 0.350, Mexico FE-SEN 0.444 for 2024, and Brazil SIN about 0.0385. The worked numbers are computed from the inputs shown: the default plant of natural gas 10,000 m3, diesel 5,000 L, gasoline 3,000 L, and LPG 2,000 L gives a Scope 1 of 43.55 tCO2e (20.20 plus 13.40 plus 6.93 plus 3.02), and with 500,000 kWh the total is 218.55 tCO2e on the US grid (Scope 2 175.00 t), 265.55 tCO2e on the Mexico grid (Scope 2 222.00 t), and 62.80 tCO2e on the Brazil grid (Scope 2 19.25 t); the US-unit facility gives a Scope 1 of 95.616 tCO2e and a total of 515.616 tCO2e with 1,200,000 kWh at 0.350; the market-based case on the Mexico grid with half the electricity certified gives a Scope 2 of 111.00 t and a total of 154.55 tCO2e; and 10,000 L of Brazil diesel B15 at 85 percent fossil gives a fossil Scope 1 of 22.78 tCO2e and a biogenic 4.02 tCO2e. 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 for the formulas and the factors above, and they are a management estimate, not a certified inventory. The tool scores the fuel and electricity you enter and cannot know every detail of your operations or the exact requirements of a given regulation; a formal filing such as the Mexico RENE, which uses SEMARNAT energy-basis factors and has a 25,000 tCO2e reporting threshold, should use the official national factors and a qualified reviewer. Set the grid factor to your own country and year, match each fuel quantity to a factor in the same unit, set the percent fossil for blended road fuel so the biogenic share splits out, and report both location-based and market-based Scope 2 so renewable certificates do not hide the physical grid. 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.