Fuel cost calculator

Frequently asked questions

Should I use my car's city, highway, or combined fuel economy rating?

Use the combined rating for mixed driving and the highway rating for trips that are mostly freeway. Real-world fuel economy also depends on load, speed, air conditioning use, and terrain, so the estimate is a planning figure rather than a precise guarantee.

Where do I find the current fuel price to enter?

Gas station price boards and fuel-price tracking apps or websites show current local prices. For a conservative estimate, round up slightly to account for price variation along your route.

Does the calculator support metric units?

Yes. Switch the efficiency unit to km/L and the distance field accepts kilometers. Enter the fuel price per liter to match. The formula is the same in either unit system: distance divided by efficiency gives volume used, which is then multiplied by price.

Why does the estimate differ from what I actually spend?

The calculation assumes a constant fuel economy across the whole trip. Stop-and-go traffic, hills, wind, vehicle load, and driving speed all affect real consumption. Treating the result as a lower bound and adding a small buffer tends to give a more reliable trip budget.