Turn distance and fuel used into MPG (US and UK), L/100 km and km/L, or price a trip. Runs on your device.
Gas mileage is the distance driven divided by the fuel used. In miles per US gallon (MPG), 300 miles on 10 US gallons is 300 ÷ 10 = 30 MPG. The page also shows the same trip in the other common units: 300 miles is 482.8032 km, 10 US gallons is 37.8541 L, so it is 482.8032 ÷ 37.8541 = 12.75 km/L, or 100 ÷ 12.75 = 7.84 L/100 km. In UK miles per gallon, which use the larger imperial gallon, it is 36.03 MPG. Type the distance and fuel in whichever units you have, and the formula box shows each conversion.
The conversions use exact definitions: 1 mile = 1.609344 km, 1 US gallon = 3.785411784 L and 1 UK (imperial) gallon = 4.54609 L. Because the UK gallon is about 20% larger, the same car has a higher number in UK MPG than in US MPG: 30 MPG (US) is 36.03 MPG (UK), and 45 MPG (UK) is 37.47 MPG (US). L/100 km works the other way round: a lower number is better, and 30 MPG (US) is 7.84 L/100 km while 40 MPG (US) is 5.88. The table lists common US MPG values in all four units, so you can read across without typing.
In trip mode, type the distance, the car's fuel economy in any of the four units, and the price of one litre, US gallon or UK gallon. The fuel needed is distance ÷ fuel economy, and the cost is the fuel times the price. A 250 mile trip at 30 MPG (US) needs 250 ÷ 30 = 8.333 gallons, which at 3.50 a gallon costs 29.17. For 500 km at 7.5 L/100 km you need 500 × 7.5 ÷ 100 = 37.5 L, and at 1.80 a litre that is 67.50. The page has no currency symbol and no default fuel price, so type your own.
The most reliable method is to fill the tank to the pump's first click-off, reset the trip meter, drive normally, then fill up again and divide the miles by the fuel added. A single tank can be off because pumps shut off differently, and a trip computer can read differently from the pump. Speed, load, tyre pressure, hills, cold weather and air conditioning all change real fuel use, so a trip cost is an estimate. This page does not know your car, fuel type or route, and it does not look up fuel prices.
Divide the miles driven by the gallons of fuel used. 300 miles on 10 US gallons is 30 MPG (US). On 10 UK gallons the same 300 miles is 30 MPG (UK), which is 24.98 MPG (US).
For US MPG divide 235.215 by the L/100 km figure; for UK MPG divide 282.481. So 7.5 L/100 km is 31.36 MPG (US) and 37.66 MPG (UK). The page does this when you enter L/100 km in trip mode.
The gallons are different sizes. A UK gallon is 4.54609 L and a US gallon is 3.785411784 L, so a car that does 30 MPG (US) does 36.03 MPG (UK). Same car, same fuel use, different number.
Fuel needed = distance ÷ fuel economy, then times the price per unit. 250 miles at 30 MPG (US) is 8.333 gallons, and at 3.50 a gallon the cost is 29.17. Switch to Trip fuel cost and type your own price.
Divide 100 by the L/100 km number. 7 L/100 km is 100 ÷ 7 = 14.29 km/L. To go the other way, 100 ÷ 14.29 gives back 7. The page shows both for every result.
No. The numbers stay in this tab and are not stored on your device or sent anywhere. Reloading the page puts the example back. The page only counts that a result was shown, without any of your numbers.