How to Calculate Gas Mileage
Calculating your vehicle's gas mileage, or fuel economy, is the best way to understand how efficiently it uses fuel. It's a crucial metric for budgeting fuel costs and monitoring your vehicle's health. A sudden drop in mileage could indicate a maintenance issue.
The Simple Method
- Fill 'er Up: Go to the gas station and fill your tank completely. Don't top off, just let the pump stop automatically.
- Reset Your Trip Meter: Before you drive away, reset your trip odometer to zero.
- Drive Normally: Use your car as you normally would until the tank is at least half empty. The longer you go, the more accurate your reading will be.
- Refill and Record: Return to the gas station and fill the tank completely again. Note the exact amount of fuel it took to refill (e.g., 12.5 gallons). Also, record the distance on your trip odometer (e.g., 350 miles).
- Calculate: Divide the distance traveled by the amount of fuel used.
Miles per Gallon (MPG) = Miles Traveled / Gallons Used
Unit Conversions: This calculator handles the conversions for you, but it's good to know them. 1 Gallon ≈ 3.785 Liters, and 1 Mile ≈ 1.609 Kilometers. L/100km is a common metric outside the US, representing how many liters it takes to drive 100 kilometers.