MPG calculator
Work out your real gas mileage from a fill-up: miles driven ÷ gallons used. You also get L/100km and your fuel cost per mile.
Compare with your car's EPA rating
Ratings from the US EPA via FuelEconomy.gov (US-market models, 1984 on). Real-world mileage is often a little lower.
The tank-to-tank method, step by step
Most MPG mistakes come from measuring the wrong fuel. Step through to see why the second fill-up, not the first, tells you what the car used.
Fill to the first click
Fill up until the pump clicks off. Don't top up. The auto shut-off is your repeatable "full" line.
Why partial fills break it: if you stop at half a tank, the pump total no longer equals what the engine burned, so one log entry reads too high and the next reads too low. They average out only if you keep logging. That is why the fuel log lets you flag partial fills.
How to calculate gas mileage by hand
MPG = miles driven ÷ gallons used
- Fill the tank completely and note the odometer (or reset the trip meter).
- Drive at least a few hundred miles if you can.
- Fill up again and note the gallons on the pump receipt.
- Divide miles by gallons. 280 mi ÷ 9.8 gal = 28.6 mpg.
Repeat over three or four tanks and average them. Weather, air conditioning, winter-blend fuel and short trips can move a single tank's figure by 10% or more. The MPG tracker keeps that running average for you. To turn MPG into a trip budget, use the fuel cost calculator.
Typical fuel economy by vehicle type
| Vehicle (recent US models) | Typical combined mpg | L/100km |
|---|---|---|
| Hybrid compact / midsize | 45–57 | 4.1–5.2 |
| Compact car (gas) | 30–36 | 6.5–7.8 |
| Midsize sedan (gas) | 28–32 | 7.4–8.4 |
| Compact SUV | 26–30 | 7.8–9.0 |
| Midsize 3-row SUV | 21–25 | 9.4–11.2 |
| Full-size pickup | 17–23 | 10.2–13.8 |
Ranges are broad class norms from EPA ratings listed on FuelEconomy.gov; check your exact model there.
Questions drivers ask
How do you calculate MPG?
Fill the tank, reset the trip meter, drive, then fill the tank again. Divide the miles on the trip meter by the gallons it took to refill. 312 miles ÷ 11.4 gallons = 27.4 mpg.
Can I use the odometer instead of the trip meter?
Yes. Write down the odometer reading at each full fill-up and subtract the previous reading to get the miles driven between them.
Why is my calculated MPG lower than the car's display?
Dashboard fuel-economy readouts are estimates and frequently read a few percent optimistic. The fill-up method measures the fuel that actually went into the tank, so it is the more trustworthy number.
What is a good MPG?
It depends on the vehicle class. In the US, new compact cars typically rate in the 30s mpg combined, midsize SUVs in the mid-20s, full-size pickups around 20, and hybrids 45–55. Compare your result to your model's rating on FuelEconomy.gov.
Is 20 MPG a lot?
20 mpg is low for a car but normal for a full-size pickup or large SUV. Recent compact cars rate in the 30s combined and hybrids in the 40s and 50s (EPA ratings on FuelEconomy.gov). At $3.50 a gallon, 20 mpg costs 17.5¢ a mile in fuel versus 11.7¢ at 30 mpg.
What is my car's miles per gallon?
Two ways: look up the official EPA rating (use "Compare with your car's EPA rating" on this page, which reads FuelEconomy.gov), or measure your real figure with the fill-up method above. The measured number is the one to budget with.
Is 300 miles per gallon possible?
Not for a regular car. 300 is usually miles per tank, not per gallon: a car that goes 300 miles on a 12-gallon tank gets 25 mpg. Divide the miles by the gallons you put in to get mpg.
How do I convert MPG to L/100km?
Divide 235.21 by US mpg (or 282.48 by UK mpg). 30 US mpg is 7.84 L/100km. The converter page does all four units at once.