Fuel Consumption Calculator Find fuel used from distance and economy. Distance mm cm m km ft yd mi AU ly Fuel economy (mpg) Fuel used (gal) 14.286 Fuel used L mL gal 54.077 Step-by-step with your numbers: 1. Values used: 2. Distance = 400 3. Fuel economy = 28 mpg 4. Fuel used = Distance / Fuel economy = 400 / 28 = 14.286gal 5. Fuel used = 54.077 Did we solve your problem today? 👍 Yes 👎 No Thanks for the feedback! How much fuel a trip uses. FAQ Round trip? Double the distance. Related calculators Fuel Cost Calculator Estimate the fuel cost of a trip. Gas Calculator Find gallons and cost for a trip. MPG Calculator Calculate fuel economy in miles per gallon.