How to calculate trip fuel cost
Divide the total trip distance by your car's fuel economy in miles per gallon to get the gallons you need, then multiply by the price per gallon. For a round trip, double the distance first. The result also shows your cost per mile, which is handy when comparing routes or cars.
Remember that real-world fuel economy is usually worse than the sticker: EPA figures don't account for traffic, loaded cars, AC on a hot day or highway speeds above 65 mph. A practical approach is to knock 10-20% off the rated MPG when estimating. If you don't know your MPG, track it for two or three tanks: miles driven divided by gallons filled.
Fuel economy reference
- Compact car: 30-40 MPG
- Mid-size sedan: 25-33 MPG
- SUV: 18-26 MPG
- Pickup: 15-22 MPG