Fuel-economy guide: km/L and litres per 100 km

When this tool helps

Fuel economy can be expressed as distance per litre or fuel per distance. A larger km/L number is better efficiency, while a smaller L/100 km number is better. Showing both measures helps prevent the common mistake of comparing them as if they used the same direction.

Enter measured kilometres travelled and litres used for that measurement. Use a consistent refuelling method and a representative distance; uncertain measurements create an uncertain result. The tool does not connect to a car, read a fuel sensor or predict future driving conditions.

What to enter

These are the candidate Android fields, not a form on this website. Editable fields in the app start empty; modes and units are selected separately.

Distance travelled (kilometres): A positive measured distance.
Fuel used (litres): The positive fuel quantity associated with that distance.

Worked example · not prefilled app data

Try this example after the update is available

The values below explain the calculation. They are not a quote, a live measurement or an automatic answer for your situation.

Distance (km): 500
Fuel used (litres): 40

Checked example result12.5 km/L

Travelling 500 km on 40 litres gives 12.5 km/L. The detail also shows 8 L/100 km, calculated as 40 ÷ 500 × 100.

Formula and assumptions

km/L = distance ÷ litres; L/100 km = litres ÷ distance × 100

Both measured values must be greater than zero. The relationship is for the same trip or measurement period.
Actual future consumption can change with driving conditions, vehicle load, route and measurement error.

A common mistake to avoid

For a cost estimate, use the km/L value in Trip fuel cost. Putting the L/100 km number into that field would reverse the intended measure.

Find this tool in the Android update

When you have the redesigned Android update, open Tools and search for Fuel economy, or find it under Travel.
Open the tool, choose the mode or units relevant to your task, then enter your own values.
Review the result and explanation. Use Calculate & save only if you want the calculation kept in local History; Copy result does not send it to our server.

This guide is an educational preview of the update in testing, not an announcement that Google Play has approved or published it. Calculations are in the native app; no web calculator or download is offered on this page.

Questions about Fuel economy

Which number should be higher for better economy?

Higher km/L indicates more distance per litre; lower L/100 km indicates less fuel for the same distance.

Does this estimate the next trip’s fuel use automatically?

No. It reports your measured trip relationship. You can deliberately reuse a suitable km/L value in the separate Trip fuel cost tool.