Calculate your MPG or L/100 km.

What is fuel economy?

Fuel economy measures how far a vehicle travels on a given amount of fuel. In the United States it's expressed as miles per gallon (MPG) — higher is better. Most of the rest of the world uses liters per 100 kilometers (L/100 km) — lower is better. They're the same idea, inverted.

The two units don't convert with a simple multiplier. A car that gets 30 MPG burns roughly 7.84 L per 100 km. A 6 L/100 km car gets about 39 MPG. Use the calculator above to switch between them.

How to measure your real-world fuel economy

Window-sticker MPG numbers come from a controlled lab cycle. Your real fuel economy depends on how, where, and what you drive. To get an honest number, use the fill-to-fill method:

1. Fill the tank completely. Note the odometer reading (call this start).
2. Drive normally until you need to fill up again.
3. Fill the tank completely. Note the odometer reading (end) and the gallons or liters added.
4. Distance = end − start. Plug that and the fuel into the calculator above.

One full-to-full reading isn't statistically meaningful — temperature, traffic, and pump cutoff all add noise. Average at least five fill-ups and you'll have a number close to your true long-term economy.

What's a "good" MPG?

For modern gasoline vehicles in 2026, rough benchmarks:

• Compact / hybrid sedan — 40–55 MPG (4.3–5.9 L/100 km)
• Mid-size sedan or crossover — 28–35 MPG (6.7–8.4 L/100 km)
• Full-size SUV or pickup — 17–22 MPG (10.7–13.8 L/100 km)
• Plug-in hybrid (charged) — 80–110 MPGe

If your number is significantly worse than the bracket for your vehicle, the usual culprits are short trips, aggressive driving, under-inflated tires, a dirty air filter, or a check-engine condition you've been ignoring.

Track fuel economy automatically with Maintory

Doing this math after every fill-up gets old fast. Maintory does it for you: tag a fuel entry as a full tank, and the app computes the MPG (or L/100 km) between successive full fills automatically. You get a clean chart of your real-world fuel economy over weeks and months — alongside the rest of your car's expenses and service history.

Related guides & calculators