# Car CO₂ Emissions Calculator

URL: https://speedycalculator.com/calculators/ecology/car-co2/
Last updated: 2026-10-25

> The car CO₂ calculator estimates carbon dioxide emitted by driving from distance, fuel economy and fuel type. Burning a litre of gasoline releases about 2.35 kg of CO₂ and a litre of diesel about 2.69 kg, based on U.S. EPA emission factors.

## Inputs

- Distance driven (km, mi)
- Fuel economy (km/L, mpg (US), mpg (UK))
- Fuel type

## Results

- Fuel burned
- CO₂ emitted
- Tree-years to absorb (≈) — Rough guide: a mature tree absorbs around 21 kg of CO₂ per year.

## Formula

```
Fuel = distance ÷ fuel economy
CO₂ = fuel × emission factor (2.348 kg/L gasoline, 2.689 kg/L diesel)
```

## Explanation

Almost all the carbon in fuel becomes CO₂ when burned, so emissions are proportional to fuel used. Cutting fuel use is the most direct way to cut driving emissions.

### How to use it

Enter distance, your car’s fuel economy and the fuel type. For a yearly footprint, enter your annual mileage.

### What is not included

This covers tailpipe CO₂ only. Fuel production, other greenhouse gases and vehicle manufacturing add more. The tree comparison is only a rough illustration.

### Inputs explained

FieldWhat to enterDistance drivenUnits: km, miFuel economyUnits: km/L, mpg (US), mpg (UK)Fuel typeChoose one: Gasoline / petrol, Diesel

### What each result means

- **Fuel burned** = [Distance driven] ÷ [Fuel economy]
- **CO₂ emitted** = [Fuel burned] × [Fuel type]
- **Tree-years to absorb (≈)** = [CO₂ emitted] ÷ 21

### Example values

How the main result changes when **Distance driven** changes and everything else stays at the example values above:

Distance driven (km)CO₂ emitted (kg)50083.9750125.81,000167.71,250209.61,500251.62,000335.4

## Worked example

1,000 km at 14 km/L on gasoline.

Fuel = 1,000 ÷ 14 ≈ 71.4 L. CO₂ = 71.43 × 2.348 ≈ **167.7 kg**.

## Key terms

- **Emission factor**: Mass of CO₂ released per unit of fuel burned.
- **Tailpipe emissions**: Gases leaving the exhaust while driving.
- **CO₂e**: Carbon dioxide equivalent, including other greenhouse gases.

## FAQ

**Why does diesel emit more per litre?**
Diesel contains more carbon per litre, though diesel cars often use fewer litres.

**How do I reduce emissions?**
Drive less, combine trips, keep tyres inflated and choose efficient vehicles.

**Are electric cars zero-emission?**
No tailpipe CO₂, but electricity generation may produce emissions.

**What formula does the Car CO₂ Emissions Calculator use?**
Fuel = distance ÷ fuel economy.


## Sources

- [U.S. EPA – Greenhouse gas emissions from a typical passenger vehicle](https://www.epa.gov/greenvehicles/greenhouse-gas-emissions-typical-passenger-vehicle)