Gas Cost Calculator
Enter the trip distance, your car's mpg and the gas price to see how much the drive will cost, per person and per mile.
How it works
Gallons used = miles ÷ mpg, and the gas cost is gallons × price per gallon. A 300-mile trip in a 28 mpg car uses about 10.7 gallons.
Gas cost by trip and fuel economy
| mi \ mpg | 20 | 25 | 30 | 35 | 40 | 50 |
|---|---|---|---|---|---|---|
| 50 mi | $8.00 | $6.40 | $5.33 | $4.57 | $4.00 | $3.20 |
| 100 mi | $16.00 | $12.80 | $10.67 | $9.14 | $8.00 | $6.40 |
| 300 mi | $48.00 | $38.40 | $32.00 | $27.43 | $24.00 | $19.20 |
| 500 mi | $80.00 | $64.00 | $53.33 | $45.71 | $40.00 | $32.00 |
| 1,000 mi | $160.00 | $128.00 | $106.67 | $91.43 | $80.00 | $64.00 |
Fuel economy conversions
| mpg (US) | L/100 km | km/L |
|---|---|---|
| 20 | 11.8 | 8.5 |
| 25 | 9.4 | 10.6 |
| 30 | 7.8 | 12.8 |
| 35 | 6.7 | 14.9 |
| 40 | 5.9 | 17.0 |
| 50 | 4.7 | 21.3 |
Real-world mileage is usually lower than the window-sticker figure on highways at high speed, in cold weather and with a loaded car.
Frequently asked questions
How do I calculate gas cost for a trip?
Divide the miles by your mpg to get gallons, then multiply by the price per gallon. 300 miles at 28 mpg and $3.20 a gallon costs about $34.29.
How do I convert mpg to L/100 km?
Divide 235.2 by the mpg: 30 mpg is 7.8 L/100 km.
Should I count the round trip?
Tick “Round trip” to double the distance. For carpools, enter the number of people to split the cost.