Fuel Economy Calculator

For 2024 model year vehicles: compact cars average 30–40 MPG combined, midsize SUVs 25–30 MPG, full-size trucks 18–24 MPG, and hybrids 45–60 MPG. The EPA calculates a combined rating at 55% city / 45% highway. Real-world MPG typically runs 10–20% below the EPA estimate due to higher speeds, AC use, cold starts, and individual driving style.

Fill your tank completely, reset your trip odometer to zero, drive normally, then fill up again. Record the miles on the odometer and the gallons needed to refill the tank. MPG = Miles driven / Gallons used. For greater accuracy, average 3–5 tanks of data. A single fill-up can be skewed by topping off technique.

L/100km measures how many litres of fuel are used per 100 kilometres — lower is better. To convert MPG to L/100km: L/100km = 235.21 / MPG. So 30 MPG = 235.21 / 30 = 7.84 L/100km. European fuel economy labels use L/100km; Canadian labels use L/100km; US labels use MPG.

At 15,000 miles/year and $3.50/gallon: 20 MPG costs $2,625/yr, 30 MPG costs $1,750/yr, 40 MPG costs $1,313/yr. The savings from improving from 20 to 30 MPG ($875/yr) are greater than improving from 30 to 40 MPG ($437/yr) — the relationship is hyperbolic. The biggest gains come from replacing low-MPG vehicles.