How do I find my fuel tank size?

Your fuel tank size is in the vehicle handbook, or you can search your car model online. Common sizes are 40-55 litres for small to medium cars, 55-70 litres for larger cars and SUVs, and 70-90 litres for some diesels and large vehicles.

How far can I drive on reserve?

Most cars have a reserve of about 10% of tank capacity. When the fuel warning light comes on, you typically have 5-8 litres remaining, giving most cars 40-80 miles of range. However, this varies by model and should not be relied upon.

Why is my actual range different from the car computer?

In-car range estimates are based on recent driving patterns. They can change significantly with driving style, terrain, and conditions. Our calculator uses your known real-world MPG for a more consistent estimate.

How far can I drive on the fuel warning light?

Most cars have about 50-70 miles of range when the fuel warning light comes on, but this varies significantly by model. Running the tank too low can damage the fuel pump (which uses fuel for cooling) and pick up sediment from the bottom of the tank. Fill up promptly when the light comes on.

How do I find my fuel tank capacity?

Check your owners manual or the manufacturers website for the official fuel tank capacity in litres. You can also fill from completely empty (fuel light on) to full to get an approximate figure. Common sizes are 40-55 litres for small/medium cars and 60-80 litres for larger cars.

CarCalcs

Fuel Tank Range Calculator

Find out how far you can drive on your current fuel level or a full tank.

Fuel Tank Size

Check your vehicle handbook for tank capacity

Current Fuel Level

Current fuel level as a percentage

Your MPG (UK)

Your fuel economy in miles per gallon

How We Calculate This

This calculator works out how many miles you can cover based on available fuel and your fuel economy.

The Formulas

Litres remaining = Tank size x (Fuel level % / 100)
Miles per litre = MPG / 4.54609
Range = Litres remaining x Miles per litre
Reserve range = 10% of tank x Miles per litre

Frequently Asked Questions

Related Calculators

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Litres Per 100km Calculator

Convert your fuel consumption to the European litres per 100km standard.

Annual Fuel Cost Calculator

Estimate your total yearly fuel spending based on mileage and consumption.

Last updated: February 2026

All calculations are estimates. Actual figures may vary based on driving conditions, vehicle specifications, and other factors.