Gas Trip Cost Calculator
Estimate the fuel cost of a trip from distance, your vehicle MPG, and the price of gas — with multi-leg trips and a round-trip option.
Result
- Total distance300.0 mi
- Fuel needed12.00 gal
- Fuel cost$42.00
- Cost per mile$0.140
Step-by-step
- Total distance = 300.0 mi.
- Fuel needed = 300.0 mi ÷ 25 MPG = 12.00 gal.
- Cost = 12.00 gal × $3.50/gal = $42.00.
How to use this calculator
- Enter the trip distance in miles (or list each leg, comma-separated, for a multi-stop trip).
- Enter your vehicle's MPG and the price of gas per gallon.
- Choose one-way or round trip.
- Read the estimated fuel cost, gallons needed, and cost per mile.
About this calculator
Planning a road trip? This calculator estimates how much you will spend on fuel from three numbers: the distance you will drive, your vehicle's fuel economy in miles per gallon, and the current price of gas. It divides the distance by your MPG to find the gallons you will burn, then multiplies by the price per gallon. You can add up a multi-stop trip by entering each leg separated by commas, and tick the round-trip option to double the distance automatically. The result includes the total gallons, the dollar cost, and a handy cost-per-mile figure for comparing routes or vehicles. For the most realistic estimate, use your real-world highway MPG rather than the optimistic EPA combined figure, since most road-trip miles are at higher, less efficient speeds.
How it works — the formula
Gallons = Distance ÷ MPG
Cost = Gallons × Price per gallon
Cost/mile = Cost ÷ DistanceDistance over fuel economy gives the fuel volume required; multiplying by unit price gives the total. Round trip simply doubles the distance before the division.
Worked examples
- Inputs:
- distance=300, mpg=25, price=3.50
- Output:
- 12 gal × $3.50 = $42.00
- Inputs:
- distance=1000, mpg=30, price=4.00
- Output:
- 33.33 gal × $4.00 = $133.33
- Inputs:
- distance=250, mpg=20, price=3.00, roundTrip=yes
- Output:
- 500 ÷ 20 × $3.00 = $75.00
Limitations
- Assumes constant MPG and a single gas price for the whole trip.
- Does not model elevation, load, or speed effects on economy.
- Liquid fuel only — not for electric vehicles.
A planning estimate; real fuel spend varies with conditions and price changes en route.