CO2 Emissions Calculator

Pick type-approval, fuel, or BEV (a fully electric car) and enter a distance. The calculator computes tank-to-wheel mass: 120 g/km over 100 km is 12 kg of CO₂. An educational model from your numbers, not a type-approval certificate and not an ESG audit.

Input data

Calculation mode
Options

Result

Enter emissions or fuel use, plus distance. CO₂ appears here.

Units follow the header. Examples on the page assume km, L/100 km, and g CO₂/kWh. A trip estimate, not a certificate. Measure economy on the fuel consumption page.

How results are calculated

Formula

Educational tank-to-wheel model (trip CO₂ mass). Type-approval: m = (EF × d) / 1000, where EF is g CO₂ per distance unit and d is distance in the same units. Fuel: m = ((L100 / 100) × dkm) × f, with f ∈ {2.31, 2.68, 1.55} kg/L. BEV: m = (E × I) / 1000, where E is trip kWh and I is grid intensity in g CO₂/kWh. Optional WTT adds a percent to trip mass.

How the result is computed (type-approval)
EF120 g/km
d100 km
m12 kg

In type-approval mode the calculator computes tank-to-wheel mass: CO₂ kilograms = grams per kilometer (or per mile on the US label) times distance in the same units, divided by 1000. 120 g/km × 100 km = 12 kg. 95 g/km over 40 km is 3.8 kg. 140 g/km over 500 km is 70 kg; with an optional 15% WTT add-on that is 80.5 kg. The g/km figure comes from what you enter (WLTP sticker, COC), not from a lab test run on this page.

In fuel mode, liters = (L/100 km × distance km) / 100, then times a built-in kg CO₂ per liter factor: petrol 2.31, diesel 2.68, LPG 1.55. 7 L/100 km of petrol over 200 km is 14 L × 2.31 = 32.34 kg. Diesel at 5.5 L/100 km over 280 km is about 41.27 kg. LPG at 9 L/100 km over 45 km is about 6.28 kg. That is a combustion path, not the same as type-approval g/km.

In BEV mode, energy in kWh = (kWh/100 km × distance) / 100, and kilograms = (kWh × grid intensity in g CO₂/kWh) / 1000. 18 kWh/100 km and 350 g/kWh over 100 km is 6.3 kg. The same trip at 16 kWh and a 650 g/kWh grid is 10.4 kg. You enter grid intensity; the calculator does not substitute a national average for you.

Fields follow the mode: grams per distance, or consumption and fuel type, or energy use and grid intensity, plus distance. Optionally compare A/B in the same mode, trips per year, and a WTT percent. The US header relabels units; an entered 120 is not converted to per-mile by itself.

Measure L/100 km on the fuel-consumption page. There is no pump price here. 7 L/100 km of petrol is not the same as 120 g/km from type-approval: one path uses liters and a factor, the other uses grams per distance unit. Ecology calculators (air travel, household) use other models and are not a renamed clone of this trip calculator.

Enter 120 and 100 in type-approval, click Calculate, and match 12 kg. That is an estimate from the educational model, not a line from a registration document and not a WLTP certificate.

How to use

  1. Pick a mode: type-approval (g per distance), fuel use and fuel type, or BEV with kWh and grid intensity.
  2. In type-approval, enter emission, for example 120, and distance, for example 100 km.
  3. Click Calculate. 120 g/km × 100 km = 12 kg. In fuel mode, 7 L/100 km of petrol over 200 km is 32.34 kg.
  4. Optionally turn on A/B compare, trips per year, or a WTT add-on, for example 15%.
  5. Examples on the page assume metric units. The result is an estimate, not a type-approval certificate.

CO₂, BEV, and WTT on this trip

Kilograms from type-approval, fuel, or the grid. 120 g/km over 100 km is 12 kg of CO₂. 18 kWh and 350 g/kWh over 100 km is 6.3 kg. WLTP is not a form field.

EF
Grams of CO₂ per distance unit in type-approval mode. 120 g/km × 100 km = 12 kg.
f
Fuel factor kg CO₂/L: petrol 2.31, diesel 2.68, LPG 1.55. 7 L/100 km of petrol over 200 km is 14 L × 2.31 = 32.34 kg.
BEV
A fully electric car: kWh from distance times grid intensity. 18 kWh/100 km and 350 g/kWh over 100 km = 6.3 kg, not zero.
WTT
Well-to-tank, an optional percent. 140 g/km over 500 km is 70 kg; with 15% WTT that is 80.5 kg. A supply-chain estimate, not tailpipe.

Usage examples

Example 1

  • Mode: intensity
  • 120 g/km
  • Distance: 100 km
  • No WTT

CO₂ ≈ 12 kg

120 g/km × 100 km → ≈ 12 kg CO₂ (type-approval mode, metric units).

Example 2

  • Mode: fuel
  • 7 L/100 km
  • Petrol
  • 200 km

CO₂ ≈ 32.34 kg

Gasoline: 2.31 kg CO₂/L × 14 L → ≈ 32.34 kg on the trip.

Example 3

  • Mode: EV
  • 18 kWh/100 km
  • Grid: 350 g/kWh
  • 100 km

CO₂ ≈ 6.3 kg

BEV: 18 kWh × 350 g/kWh → ≈ 6.3 kg (grid use, not manufacturing).

Example 4

  • Mode: type-approval
  • Emission: 95
  • Distance: 40

CO2 ≈ 3.8 kg

How much CO2 on a 40 km commute at 95 g/km? ≈ 3.8 kg.

Example 5

  • Mode: fuel
  • Consumption: 5.5
  • Fuel type: diesel
  • Distance: 280

CO2 ≈ 41.27 kg

How much CO2 on a 280 km highway run at 5.5 L/100 km diesel? CO2 ≈ 41.27 kg.

Example 6

  • Mode: fuel
  • Consumption: 9
  • Fuel type: lpg
  • Distance: 45

CO2 ≈ 6.28 kg

How much CO2 on a 45 km city loop on LPG at 9 L/100 km? CO2 ≈ 6.28 kg.

Example 7

  • Mode: BEV
  • Energy use: 16
  • Grid intensity: 650
  • Distance: 100

CO2 ≈ 10.4 kg

How much CO2 for a BEV at 16 kWh/100 km and a 650 g/kWh grid over 100 km? CO2 ≈ 10.4 kg.

Example 8

  • Mode: type-approval
  • Emission: 140
  • Distance: 500
  • Add estimated well-to-tank add-on: yes
  • WTT add-on (%): 15

CO2 ≈ 80.5 kg with 15% WTT

How much CO2 on 500 km at 140 g/km plus a 15% well-to-tank add-on? CO2 ≈ 80.5 kg with 15% WTT.

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FAQ

How do I calculate trip CO2 emissions?

In type-approval mode: mass kg = (g per km × distance) ÷ 1000. Example: 120 g/km × 100 km → 12 kg. In fuel mode: liters from L/100 km × distance, then × kg CO₂ per liter. For a BEV: kWh × grid g/kWh ÷ 1000.

How much CO2 is 120 g/km over 100 km?

12 kg of CO₂ tank-to-wheel. That is mass from the numbers you enter in type-approval mode, not a type-approval certificate and not an ESG audit.

Does the result replace a WLTP type-approval certificate?

No. The calculator uses the numbers you enter. It is not a type-approval certificate, a WLTP sticker, or an ESG report.

Is this a full vehicle life-cycle carbon footprint?

No. The model covers trip emissions (tailpipe / fuel / grid, optional WTT). It omits vehicle manufacturing, end-of-life, and the full supply chain.

Is this a free CO2 emissions calculator?

Yes. Pick a mode, enter distance and parameters, and you see trip CO₂ mass at once. No account required.

How does type-approval mode (g per distance) work?

CO₂ kilograms = grams per distance unit × distance, divided by 1000. That is tank-to-wheel mass from the figure you enter. 120 g/km × 100 km = 12 kg. The calculator is not a WLTP or COC certificate.

How does fuel mode differ from g/km?

Fuel mode computes liters from consumption and distance, then multiplies by a built-in kg CO₂/L factor (petrol 2.31, diesel 2.68, LPG 1.55). Type-approval uses g/km. Those are two paths, not one formula. A/B compare shows the kilogram gap with the same mode on both sides.

What does the optional WTT add-on mean?

Well-to-tank is an estimated percent added to trip emissions (well to tank). The default is 15% when you enable the option. It is not a tailpipe measurement and not a full well-to-wheel LCA audit.

Does a BEV show zero emissions here?

At the tailpipe, yes. In this calculator a BEV multiplies energy use (kWh from distance) by the grid intensity you enter. 18 kWh/100 km and 350 g/kWh over 100 km is 6.3 kg. Zero at the tailpipe is not zero in the result.

Where do the fuel factors come from?

They are built into the script: petrol 2.31 kg CO₂/L, diesel 2.68, LPG 1.55. You do not enter them by hand. They are tank-to-wheel combustion factors in this educational model, not a registration-document field.

Does A/B compare change the chemistry?

No. The same mode runs on both scenarios. The calculator shows kilograms for A and B and the absolute difference. It does not mix type-approval with fuel in one result row.

Does the result replace type approval or ESG?

No. It is an educational model from the numbers you enter. It does not replace WLTP, a COC, or an ESG audit.

Does the US unit switch convert an entered 120?

No. On an empty field it relabels units. It does not multiply an entered number by a mile factor. Examples on the page assume km, L/100 km, and g CO₂/kWh.

What are trips per year and the WTT percent for?

Trips per year scales trip emissions into an annual estimate. The WTT percent applies only when you enable the well-to-tank add-on. Both fields are optional.

Where do I measure fuel use versus a fuller CO₂ path?

Measure L/100 km on the fuel-consumption calculator. Here you compute trip CO₂ mass from type-approval, fuel, or the grid. Air-travel RFI and household ecology cards use different formulas.

· Hubert Ligocki

At 120 g/km and 100 km the tank-to-wheel result is 12 kg of CO₂. A model from your numbers, not a WLTP certificate.

Knowledge sources

Trip emissions come from the numbers you enter. Below is context for tank-to-wheel, fuel factors, and grid intensity — not a type-approval certificate.

Page updated October 15, 2026.