Fleet Fuel & Carbon ROI Calculator

• Total annual fuel = fleet size × average annual fuel per vehicle, vessel, machine or engine — in litres, US gallons (fuels sold by the gallon in the United States, Colombia and Guatemala), kilograms (CNG and LNG on the road, and LPG in Colombia, where the official emission factor is per kilogram), kilowatt-hours (natural gas, gross calorific value) or tonnes (marine fuels). In the United States, CNG is counted in gasoline gallon equivalents (GGE) and LNG on the road in diesel gallon equivalents (DGE), as they are sold at the pump — the US model rule for the retail sale of vehicle fuel, which the states adopt, sets 1 GGE at 5.660 lb of compressed natural gas and 1 DGE at 6.059 lb of liquefied natural gas (NIST Handbook 130, 2026, section 2.27); natural gas is counted in MMBtu (1 MMBtu is 10 therms), and biomethane in GGE on the road and in MMBtu for power generation.
• Fuel saved = total annual fuel × your reduction assumption.
• Fuel cost saved = fuel saved × the fuel price you enter.
• CO₂ avoided = fuel saved × emission factor ÷ 1000 → metric tonnes. This is a calculation from the fuel figure, not a measurement. Factors are direct combustion (tank-to-wheel) CO₂ values from the UK Government's 2026 GHG conversion factors, except for ships, some biofuels, the United States, Colombia and Guatemala: in the United States, petrol, diesel and LPG use the US EPA's factors per US gallon and natural gas its factor per MMBtu (Emission Factors Hub, 2025 edition); for CNG and LNG the factor is calculated from that natural-gas factor and the energy in a GGE or DGE (5.660 lb × 22,453 Btu/lb and 6.059 lb × 23,726 Btu/lb, higher heating values from the US Department of Energy's Alternative Fuels Data Center); and HVO, B100 and biomethane use the UK values converted to US units (biomethane per MMBtu with the heating value of CNG, also a calculation); in Colombia, diesel and petrol use the factors per US gallon and LPG the factor per kilogram published by the Colombian Mining and Energy Planning Unit (UPME, FECOC 2016), and HVO and B100 the UK values converted to US gallons; in Guatemala, which sells fuel by the US gallon but for which no official emission factor per gallon was found, petrol, diesel and LPG use the US EPA’s factors per US gallon instead, and HVO and B100 the UK values converted to US gallons; the factor and its source are shown next to the fuel you select. Fossil gas fuels on land are counted as CO₂ only. Ships are shown in CO₂e: CO₂ plus methane (× 28) and nitrous oxide (× 265; global warming potentials from Delegated Regulation (EU) 2020/1044) with the EU's standard emission factors (MRV Regulation (EU) 2015/757, Annex I), because the EU ETS counts all three gases for shipping since 2026 (European Commission, FAQ on maritime transport in the EU ETS); for LNG the factor includes the methane slip that the EU sets for the engine type (a standard value, not a measurement). Some biofuels are shown differently too: HVO and biomethane count only methane and nitrous oxide, because their CO₂ is set to net zero by the standard reporting convention (it was absorbed when the biomass grew); B100 (pure biodiesel) is shown as a mixed CO₂e figure, because part of its published factor is genuine fossil CO₂ from how it is made, not from the biomass itself. The note next to each of these fuels explains what its own figure does and doesn't count. For the blends offered for a country — E5, E10 and B7 where they are standard grades at the pump (Germany, several other EU countries and the UK), B7 and E5 in Switzerland and Liechtenstein, E10 in Iceland, the United States, Canada, Australia and Ukraine, B5 in Australia and E5 in Indonesia for fuel bought as such, B7 in Iceland as a model assumption, E5 RON92 and E10 in Vietnam, B3 and E10 in the Philippines, B4 in Korea, B50 in Indonesia, B15, B20, B10 and B7 in Malaysia, E20 in India, B10 and E10 in Colombia, B15, E32 and premium E25 in Brazil, E10 in Guatemala, petrol with bio-ETBE in Japan, petrol with ethanol in Uruguay, and in the United States the diesel grades that state law sets in Minnesota (B20 from mid-April to September, B5 from October to March), Oregon (B5) and Pennsylvania (B2 on the road), the City of Portland’s 50% grade for road vehicles, and the state averages of California, Oregon and Washington — the factor is calculated: the 100% mineral factor × the fossil share at the biofuel content the fuel's standard allows at most (up to 7% biodiesel in B7 and 5% in Australia's B5, up to 5% or 10% ethanol in E5 and E10; Vietnam's E5 RON92 may carry less than 7.5% ethanol, counted as 7.5%) — or, where a national, state or city mandate sets the blend, at the mandated share (the Philippines' B3 and E10 and Korea's 4% biodiesel, which suppliers must blend at least, the minimum shares that Minnesota, Oregon, Pennsylvania and the City of Portland set for the diesel sold there, and the set shares of Colombia's B10 and E10, Brazil's B15, E32 and E25, Indonesia's B50, Malaysia's B10 and B7 and Guatemala's E10) — or, for Malaysia's B15 and B20, at the share of the government programmes — or, for Japan, Uruguay and India, at the national average (about 1.9% ethanol counted in bio-ETBE in Japan, about 9.8% ethanol in Uruguay, about 20% in India) — or, for diesel in California, Oregon and Washington, at the state average that we calculate from the volumes reported to their clean-fuel programmes over the last four quarters (about 68%, 27% and 12% renewable diesel and biodiesel) — with the biogenic share counted as zero. The biofuel content of the fuel you actually buy varies, so the fossil CO₂ may be higher or lower than shown — treat it as a model assumption.
• Carbon price — shown the way it actually reaches you:
  • Already included in your fuel price (for example Germany's national emissions trading scheme or Japan's carbon tax): shown as “of which carbon price already in your fuel cost” for information. It is not added to the saving, because the fuel price you enter already contains it.
  • Paid on top through emissions trading or a carbon tax on the site (for example the EU or UK ETS for qualifying ships and large combustion sites, the Dutch CO₂ levy on greenhouse businesses’ natural gas, or Latvia’s CO₂ tax on permitted, licensed or registered combustion plants of 20 MW or less outside the EU ETS): the avoided emissions the scheme prices (CO₂; for ships CO₂e where the scheme also counts methane and nitrous oxide, as the EU ETS does) × carbon price × the share of emissions covered, added to the saving. Sites formally excluded from the EU ETS as small emitters may face national measures instead — in Croatia, for example, an annual fee linked to the price of EU allowances; these are not modelled here.
  • No carbon price reaching your fuel: no carbon line.
• Total annual saving = fuel cost saved + any emissions-trading cost or carbon tax paid on top of fuel that is avoided.

Carbon prices and coverage rules are indicative, dated and sourced next to each figure; your own contract prices and your regulator's rules take precedence. See the regulatory context for background.