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Fuel Efficiency Calculator

Calculate MPG and L/100km, plus optional cost and emissions context.

Enter a distance and either the fuel you used or your MPG. We will calculate MPG and L/100km, and show the estimated fuel cost using the latest UK weekly average price.

Looking for a full trip cost? Try the journey cost calculator for price comparisons and best-value guidance. For regional context, browse the locations hub .

When to use this calculator

Use this when you know either litres used or MPG and want a clear efficiency and cost picture in UK units.

Inputs

UK units

Fuel info

Price contextGov.uk weekly average

National average 148.8p/L (week of 2026-03-30).

Results

Enter your details to calculate

Fill in the form to see your results.

How this is calculatedv
  1. Enter trip distance and either litres used or MPG.
  2. We convert between MPG and L/100km automatically.
  3. If price data is available, we also estimate trip fuel cost and emissions context.

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