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Tank Range Calculator

Estimate full-tank range from usable fuel capacity and UK MPG.

Use this calculator

Enter usable tank litres and UK MPG.

What your result means

The result is the theoretical distance available from the usable litres and UK MPG entered. It is most helpful for comparing tank capacities or setting a conservative refuelling plan, rather than predicting an exact dashboard range.

Worked example

Using 50 usable litres and 45 UK MPG:

Estimated range
494.9 miles
Kilometres
796.5 km
UK gallons
11

Treat this as a full-to-empty mathematical range, not a reserve-free travel promise.

Formula

Miles=Usable litres4.54609×UK MPG\text{Miles}=\frac{\text{Usable litres}}{4.54609}\times\text{UK MPG}

Tank size and estimated range at 45 UK MPG

Usable litresEstimated milesEstimated km
35 litres346.5 miles557.6 km
40 litres395.9 miles637.2 km
45 litres445.4 miles716.9 km
50 litres494.9 miles796.5 km
55 litres544.4 miles876.2 km
60 litres593.9 miles955.8 km
65 litres643.4 miles1,035.5 km

Plan with a reserve

Use usable fuel rather than the published nominal tank capacity if you do not intend to run close to empty. Keeping a reserve margin helps account for traffic, diversions and real-world MPG changes.

Assumptions and limitations

  • UK / imperial MPG is used.
  • Nominal and usable tank capacity can differ.
  • Speed, weather, load, gradient and driving style affect real range.

Helpful questions

Is this the same as dashboard range?

No. Dashboard range can use recent driving data; this uses the fixed MPG entered.

Should I enter nominal tank capacity?

Enter the litres you genuinely plan to use, which may be lower than nominal capacity.

Why keep a reserve?

It reduces the risk created by changing conditions or an unavailable fuel station.

Does this include fuel already used?

No. Enter the usable fuel currently available.

Does it calculate fuel cost?

No. Use the full-tank-cost calculator for a price estimate.

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