How do I use metric units?

Choose km/L mode. Enter kilometres for distance and price per litre.

What if I know L/100 km instead of km/L?

Convert with the Fuel Economy tool first, then enter km/L here, or invert: km/L = 100 ÷ (L/100 km).

Does this include tolls or parking?

No. For a fuller trip budget, use Road Trip Cost or Trip Cost.

Why is my real cost higher?

Cold starts, hills, traffic, and a heavy load lower real efficiency. Add a margin if you need a safe budget.

Fuel Cost Calculator

Cars

Estimate fuel cost from distance, efficiency, and price per unit.

Distance

Efficiency (mpg or km/L)

Price per gallon or litre

Mode

Results update as you type.

Last updated 3 October 2026

How to use

Enter distance, fuel efficiency, and price per unit. Choose mpg (miles and gallons) or km/L (kilometres and litres). The result shows fuel volume and cost.

Formula

fuel = distance ÷ efficiency
cost = fuel × price

Worked example

300 mi ÷ 25 mpg × $3.50 per gallon → 12 gallons and $42.00.

Assumptions

Efficiency is treated as steady for the whole trip.
City and highway mix, wind, and load change real consumption.
Currency is whatever unit you use for price; the tool does not convert currencies.

FAQs

How do I use metric units?: Choose km/L mode. Enter kilometres for distance and price per litre.
What if I know L/100 km instead of km/L?: Convert with the Fuel Economy tool first, then enter km/L here, or invert: km/L = 100 ÷ (L/100 km).
Does this include tolls or parking?: No. For a fuller trip budget, use Road Trip Cost or Trip Cost.
Why is my real cost higher?: Cold starts, hills, traffic, and a heavy load lower real efficiency. Add a margin if you need a safe budget.