Fuel Cost Calculator
Estimate the fuel cost for any trip based on distance, vehicle fuel efficiency and current gas price.
How to use the Fuel Cost Calculator
- Enter your inputs into the Fuel Cost Calculator above.
- Results update instantly as you type — no submit button needed.
- Adjust any value to see how the result changes in real time.
The fuel cost formula
Cost = (Distance / MPG) × Price per gallon
Divide trip distance by MPG to get gallons needed, multiply by price per gallon for total fuel cost. Works with metric units (L/100km × distance/100 × price/L) too.
Worked example
A 500-mile trip in a 28-MPG vehicle at $4.20/gallon: gallons = 500/28 ≈ 17.86; cost = 17.86 × $4.20 ≈ $75.01.
Frequently asked questions
Should I use city or highway MPG?
For long road trips, highway MPG is closer to actual consumption. For mixed driving, the EPA "combined" figure is a fair estimate. Real-world MPG often runs 10–15% below EPA ratings.
Does speed affect fuel cost?
Yes — most cars are most fuel-efficient at 50–60 mph. Above 70 mph, aerodynamic drag rises sharply; MPG can drop 15–20% at 80 mph vs. 65 mph.
What about EV trips?
EV trip cost = (Distance / efficiency_mi_per_kWh) × cost_per_kWh. A 250-mile trip at 3.5 mi/kWh and $0.14/kWh: 71.4 kWh × $0.14 ≈ $10.