Fuel Cost Calculator
Estimate trip fuel cost from distance, economy, and price per unit. Fully client-side — no account, uploads, or remote storage.
Added Apr 18, 2026
Input
Result
Enter a value for unit system to see your result.
How it works
Calculates the fuel cost for a trip given distance, vehicle fuel efficiency, and fuel price. Supports both metric (L/100km) and imperial (miles per gallon) units.
Formula
Fuel used (L) = Distance (km) × Efficiency (L/100km) ÷ 100
- Fuel used
- Litres or gallons needed for the trip
- Distance
- Total trip distance in km or miles
- Efficiency
- L/100km or miles per gallon (MPG)
Step by step
- 01Choose metric or imperial units.
- 02Enter trip distance, vehicle fuel efficiency, and current fuel price.
- 03Metric: fuel = distance × efficiency ÷ 100; cost = fuel × price per litre.
- 04Imperial: fuel = distance ÷ mpg; cost = fuel × price per gallon.
Examples
200 km trip, 8 L/100km, $1.80/L
200 km × 8 L/100km ÷ 100 = 16 litres; 16 × $1.80 = $28.80.
Inputs
- Unit system:
- metric
- Distance:
- 200
- Fuel efficiency:
- 8
- Fuel price:
- 1.8
Result
- Total fuel cost:
- $28.80
- Fuel used:
- 16.0 L
120 miles, 30 mpg, $3.50/gal
120 miles ÷ 30 mpg = 4 gallons; 4 × $3.50 = $14.00.
Inputs
- Unit system:
- imperial
- Distance:
- 120
- Fuel efficiency:
- 30
- Fuel price:
- 3.5
Result
- Total fuel cost:
- $14.00
- Fuel used:
- 4.0 gal
Frequently asked questions
How do I convert L/100km to MPG?
Divide 235.21 by the L/100km value. For example: 8 L/100km = 235.21 ÷ 8 ≈ 29.4 mpg.
Why does fuel efficiency matter for cost?
A car that uses 6 L/100km instead of 8 L/100km saves 25% on fuel for every trip — equivalent to getting a 25% discount on fuel prices.