FuelBench
MPG Calculator
Miles driven and gallons used — get your real-world MPG and the L/100km equivalent.
MPG and L/100km for common fill-up and trip-meter combinations
Miles driven divided by gallons pumped, with the metric equivalent from 235.21 divided by MPG. Each row is a realistic tank-to-tank measurement for that class of vehicle, which is exactly what the calculator does with your own two numbers.
| Vehicle type | Miles driven | Gallons used | Fuel economy (MPG) | Metric (L/100km) |
|---|---|---|---|---|
| Full-size pickup | 240 | 16.0 | 15.0 | 15.68 |
| Large SUV | 300 | 15.0 | 20.0 | 11.76 |
| Midsize SUV or crossover | 320 | 12.8 | 25.0 | 9.41 |
| Midsize sedan | 350 | 12.0 | 29.2 | 8.06 |
| Compact sedan | 300 | 10.0 | 30.0 | 7.84 |
| Compact hatchback | 400 | 12.0 | 33.3 | 7.06 |
| Efficient compact, mixed driving | 380 | 10.0 | 38.0 | 6.19 |
| Efficient compact, highway | 420 | 10.0 | 42.0 | 5.60 |
| Hybrid, mixed driving | 450 | 9.0 | 50.0 | 4.70 |
| Hybrid, best case | 500 | 9.0 | 55.6 | 4.23 |
MPG and L/100km run in opposite directions: higher MPG is better, lower L/100km is better. For a reading you can trust, fill the tank completely, reset the trip meter, drive normally until the next fill-up, and divide the trip miles by the gallons the pump actually delivered. A single tank can be several MPG out because of how full the last fill was, so average three or four tanks. Expect your real figure to sit below the EPA sticker: highway speeds, cold starts, roof boxes, towing and stop-and-go traffic all cost fuel that a lab test does not see.
Why your real MPG differs from the sticker number
EPA/manufacturer MPG ratings come from standardized lab tests — real-world driving (traffic, climate control, driving style, terrain) almost always produces a different number, which is exactly what this calculator measures from your actual fill-ups.
MPG vs. L/100km — opposite directions
MPG is 'distance per unit of fuel' (higher is better), while L/100km is 'fuel per unit of distance' (lower is better) — the two scales run in opposite directions, which is a common source of confusion when comparing cars across regions.
Frequently asked questions
I drove 350 miles on 12 gallons — what's my MPG?
29.2 MPG (350 / 12). That's solid for a midsize sedan. Fill up fully, reset your trip meter, drive until the next fill-up, and divide miles driven by gallons pumped for the most accurate real-world figure.
Why is my actual MPG lower than the EPA sticker?
EPA ratings come from standardized lab tests. Real-world driving includes highway speeds above the test speed, aggressive acceleration, stop-and-go traffic, climate control use, and cold weather — all of which reduce fuel economy.
How do I convert MPG to L/100km?
Divide 235.215 by your MPG. For example, 30 MPG = 235.215 / 30 = 7.84 L/100km. This calculator does the conversion automatically.
How does this relate to the fuel cost calculator?
This calculator tells you your car's efficiency (MPG). The fuel cost calculator uses that MPG figure along with distance and gas price to estimate total fuel cost for a specific trip.
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OpenLast updated: September 6, 2026