PetrolCalculator

Fuel calculator

Full Tank Cost Calculator

Estimate the cost of filling your car’s tank from its capacity, current fuel level and the price at the pump.

Use this calculator

Enter tank details and fuel price to estimate the cost of filling it.

What your result means

This is the estimated cost of the fuel needed to fill the unused part of the tank. It depends on the tank capacity, your indicated fuel level and the price per litre entered.

Worked example

Using a 55-litre tank that is 25% full at 142p per litre:

Fuel needed
41.3 litres
Estimated cost
£58.58

The calculator estimates the missing fuel, not the cost of a full tank from empty.

Formula

Litres needed=Tank capacity×(1−fuel level/100)\text{Litres needed}=\text{Tank capacity}\times(1-\text{fuel level}/100)
Cost (£)=Litres needed×Price (p/litre)/100\text{Cost (£)}=\text{Litres needed}\times\text{Price (p/litre)}/100

55-litre tank at 142p per litre

Current fuel levelFuel neededEstimated cost
0%55 litres£78.10
25%41.3 litres£58.58
50%27.5 litres£39.05
75%13.8 litres£19.53

Helpful questions

How accurate is the estimate?

It is only as accurate as the tank capacity, fuel-level reading and price entered. Pump cut-off and dashboard readings can vary slightly.

Can I calculate a full tank from empty?

Yes. Enter 0% as the current fuel level.

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