Fuel consumption calculator (odometer)
Fill the tank to the top and note the odometer; at the next full fill-up enter the new reading and the liters to get your real consumption.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter odometer at previous fill-up, odometer now and liters filled now.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Distance = end reading − start reading. L/100 km = liters ÷ distance × 100; km/L = distance ÷ liters; US mpg = 235.2146 ÷ (L/100 km), UK mpg = 282.4809 ÷ (L/100 km).
Example
Inputs: Odometer at previous fill-up = 12,000 km, Odometer now = 12,450 km, Liters filled now = 36 L. Result: Consumption: 8 L/100 km; Kilometers per liter: 12.5 km/L; Miles per US gallon: 29.4 mpg (US).
Limits and caveats
- Accuracy depends on filling the tank to the brim both times, ideally at the same pump.
- Car odometers can be off by a small margin, especially after a tire size change.
Questions about this tool
Why does it differ from the dashboard figure?
The dashboard estimates consumption from engine sensors, while the fill-up method measures the fuel you actually paid for.
Should I use more than one fill-up?
Yes. Adding the liters and distance of several fill-ups gives a steadier average and smooths out uneven fills.
What is the difference between US and UK gallons?
A US gallon is 3.785411784 L and a UK gallon is 4.54609 L, so the UK mpg figure is higher for the same car.