How to calculate fuel cost
A car's miles per gallon (MPG) is the miles it goes on one gallon of gas. So the miles you drive ÷ MPG is the gallons you'll use, and gallons × the price of a gallon is what the gas costs.
Here it is with your numbers:
- Gallons needed: 250 ÷ 25 = 10.
- Cost: 10 × $4.00 = $40.00.
It means the trip costs $40.00 in gas.
Source FuelEconomy.gov (U.S. Department of Energy and EPA) · How to Calculate Your MPG ↗
Trip cost at different gas prices
Gas prices change every week. Here is the same trip at prices a little lower and higher than yours.
| Price per gallon | Trip cost |
|---|---|
| $3.50 | $35.00 |
| $3.75 | $37.50 |
| $4.00 | $40.00 |
| $4.25 | $42.50 |
| $4.50 | $45.00 |
Today's gas prices
The U.S. Energy Information Administration (EIA) publishes the average price of a gallon of regular gas every week, for the whole country and for each region, with all taxes included. Prices differ a lot by region, so the price at your local pump is the best number to use.
Source U.S. Energy Information Administration · Gasoline and Diesel Fuel Update (weekly prices) ↗
Find your car's MPG
The most accurate MPG is your own: fill the tank, note the miles, and at the next fill-up divide the miles driven by the gallons it took.
FAQs
How do I calculate the cost of gas for a trip?
Divide the miles by your car's miles per gallon, then multiply by the price of a gallon. 250 miles at 25 MPG uses 10 gallons; at $4.00 a gallon that's $40.00. For a round trip, double the miles first.
Source FuelEconomy.gov (U.S. Department of Energy and EPA) · How to Calculate Your MPG ↗
How much does $20 of gas get you?
Divide $20 by the price of a gallon, then multiply by your MPG. At $4.00 a gallon, $20 buys 5 gallons, which takes a 25 MPG car 125 miles.
How many miles is $50 in gas?
At $4.00 a gallon, $50 buys 12.5 gallons. A car that gets 25 MPG goes 312.5 miles on that (12.5 × 25). Use your own price and MPG: miles = dollars ÷ price × MPG.
How much is 14 miles of gas?
14 miles at 25 MPG uses 0.56 gallons (14 ÷ 25). At $4.00 a gallon that costs $2.24.
Sources
- FuelEconomy.gov (U.S. Department of Energy and EPA): How to Calculate Your MPG
- U.S. Energy Information Administration: Gasoline and Diesel Fuel Update (weekly prices)