Checks Out
All calculators
UtilityLive

Fuel Cost Calculator

Enter trip distance, your car's MPG and the fuel price.

Short answer

Cost = (distance ÷ MPG) × 4.546 × (price per litre ÷ 100). The 4.546 converts gallons (UK) to litres.

Trip

miles
MPG
p/litre

Fill in the fields above to see your result instantly.

Calculation method, coverage and version

Inputs used
Distance, Fuel economy, Fuel price, Round trip (×2).
Calculation approach
The calculator applies the rules and assumptions described in “How it works” to the values you enter. Rounding can cause small differences from an official or provider calculation.
Coverage
Utility. UK nations, tax treatment, local rules and provider criteria can differ; check the official sources shown below before acting.
Content version
No page-specific review date is currently published. Treat the result as indicative and verify current rules independently.
Not included unless explicitly requested: personal circumstances not entered, provider discretion, future rule changes, professional fees and case-specific exceptions. Read the full calculator methodology.

How it works

UK MPG uses the imperial gallon (4.546 L). Convert miles → gallons → litres → cost using your pence-per-litre price.

Worked example

100 miles at 45 MPG, fuel 150p/L: 100/45 = 2.22 gal × 4.546 = 10.10 L × £1.50 = £15.15.

Who should use this

  • •Drivers planning a long trip
  • •Mileage expense claims
  • •Comparing two cars' running cost

Common mistakes

  • ×Using US MPG (smaller gallon) — UK MPG is 20% bigger
  • ×Forgetting a round trip

Frequently asked questions

Why isn't my real MPG matching the brochure?▾

Manufacturer MPG is from a lab test (WLTP). Real-world is usually 10–25% lower.

Related calculators

Car Running Costs →EV Charging Cost →Mileage Claim Calculator →