Fuel Cost Calculator
Estimate how much fuel a trip will use and what it will cost. Works in US units (miles, MPG, $/gallon) or metric (km, L/100 km, price per liter).
How to use the Fuel Cost Calculator
- Choose US or metric units.
- Enter the trip distance, your vehicle’s fuel economy and the fuel price.
- Choose one way or round trip.
How it works
In US units, gallons = miles ÷ MPG. In metric, liters = km × L/100 km ÷ 100. Multiply the fuel used by the price to get the cost. To convert between the two systems, L/100 km = 235.21 ÷ MPG (US).
Cost of a 100-mile drive at $3.50/gal
| MPG | Gallons | Cost | L/100 km |
|---|---|---|---|
| 15 | 6.67 | $23.33 | 15.7 |
| 20 | 5 | $17.5 | 11.8 |
| 25 | 4 | $14 | 9.4 |
| 30 | 3.33 | $11.67 | 7.8 |
| 35 | 2.86 | $10 | 6.7 |
| 40 | 2.5 | $8.75 | 5.9 |
| 50 | 2 | $7 | 4.7 |
Frequently asked questions
How do I calculate gas cost for a trip?
Divide the distance by your MPG to get gallons, then multiply by the price per gallon.
What is 30 MPG in L/100 km?
About 7.8 L/100 km.
How can I reduce fuel cost?
Keep tires properly inflated, drive smoothly, avoid high speeds and remove unnecessary weight.
How do I work out my real MPG?
Fill the tank, reset the trip meter, drive normally, then refill. Divide the miles driven by the gallons needed to refill — that is your real-world MPG.