Fuel Economy Converter (Mileage)
Mileage in km/L, L/100 km or mpg (US or UK) — exact, both directions.
Type a figure in plain words — “15 km/l to L/100 km”, “25 mpg to km/L”, “45 mpg UK to L/100 km”, “6.5 L/100 km in mpg” — or use the boxes below.
Rounded · L/100 km = 100 ÷ km/L · 1 km/L = 100 L/100 km
- Kilometres per litre: distance covered on one litre: the “mileage” figure used in India and Japan
- Litres per 100 km: fuel used to drive 100 km: the official figure in Europe, Australia, Canada and China
Compare two vehicles
The fuel — and, with a price, the money — each uses over the same distance. The two figures may be in different units.
10,000 when empty; a year of your own driving is a good choice.
In any currency: the costs come out in the same one.
Type the fuel economy of both vehicles.
15 km/L in every unit
Select a unit to convert to it. Values marked ≈ are rounded; all others are exact.
| Unit | Value | Copy |
|---|---|---|
| Distance per fuel (higher is better) | ||
| from | 15 | |
| 35.2821875 | ||
| ≈ 42.37214045 | ||
| Fuel per distance (lower is better) | ||
| to | ≈ 6.666666667 | |
| ≈ 2.834291383 | ||
Convert a list of values
Up to 1,000 lines. Fractions (3/4), mixed numbers (1 1/2) and grouped digits (1,250) are fine.
| Value | Result |
|---|
Common values
| km/L | L/100 km | mpg (US) | mpg (UK) | gal/100 mi |
|---|---|---|---|---|
| 5 | 20 | ≈ 11.76 | ≈ 14.12 | ≈ 8.503 |
| 8 | 12.5 | ≈ 18.82 | ≈ 22.6 | ≈ 5.314 |
| 10 | 10 | ≈ 23.52 | ≈ 28.25 | ≈ 4.251 |
| 12 | ≈ 8.333 | ≈ 28.23 | ≈ 33.9 | ≈ 3.543 |
| 14 | ≈ 7.143 | ≈ 32.93 | ≈ 39.55 | ≈ 3.037 |
| 15 | ≈ 6.667 | ≈ 35.28 | ≈ 42.37 | ≈ 2.834 |
| 16 | 6.25 | ≈ 37.63 | ≈ 45.2 | ≈ 2.657 |
| 18 | ≈ 5.556 | ≈ 42.34 | ≈ 50.85 | ≈ 2.362 |
| 20 | 5 | ≈ 47.04 | ≈ 56.5 | ≈ 2.126 |
| 22 | ≈ 4.545 | ≈ 51.75 | ≈ 62.15 | ≈ 1.932 |
| 25 | 4 | ≈ 58.8 | ≈ 70.62 | ≈ 1.701 |
| 30 | ≈ 3.333 | ≈ 70.56 | ≈ 84.74 | ≈ 1.417 |
| 35 | ≈ 2.857 | ≈ 82.33 | ≈ 98.87 | ≈ 1.215 |
| 40 | 2.5 | ≈ 94.09 | ≈ 113 | ≈ 1.063 |
Values marked ≈ are rounded to 4 significant digits. Higher km/L and mpg, and lower L/100 km and gal/100 mi, mean less fuel.
About the Fuel Economy Converter (Mileage)
Convert fuel economy between km/L (the “mileage” of India and Japan), L/100 km (Europe, Australia, Canada), mpg (US), mpg (UK) and US gallons per 100 miles (the consumption figure on US fuel economy labels). Some of these measure distance per fuel and the others fuel per distance, so the conversion is a division, not a multiplication — 15 km/L is 100 ÷ 15 ≈ 6.667 L/100 km — and this page does it with exact fractions of the legal mile (1,609.344 m), US gallon (3.785411784 L) and imperial gallon (4.54609 L).
Under the result you see the fuel for 100 km and for 100 miles. Compare two vehicles works out how much fuel — and, with a price, how much money — each uses over a distance, whatever units their figures are in, and the table below lists common values in every unit. A bare “mpg” is read as US gallons, or as imperial gallons when your country is the UK.
How to use it
- Type a figure in From and pick its unit, then pick the unit you want in To — or type
25 mpg to L/100 kmin Quick convert and press Enter. - Read the result, the formula and the fuel for 100 km and 100 miles; the table under the converter shows the same figure in every unit.
- To compare two cars, type each one’s figure in Compare two vehicles (they may be in different units), the distance and, optionally, the fuel price in any currency.
- Pick the unit of the Common values table, copy it, or copy a link to your result.
Examples
15 km/L to L/100 km
≈ 6.667 L/100 km
25 mpg to L/100 km
≈ 9.409 L/100 km
A bare “mpg” is US gallons unless your country is set to the UK.
45 mpg UK to L/100 km
≈ 6.277 L/100 km
6.5 L/100 km to mpg
≈ 36.19 mpg (US), ≈ 43.46 mpg (UK)
25 mpg to gal/100 mi
4 gal/100 mi
Gallons per 100 miles = 100 ÷ mpg.
A 15 km/L, B 20 km/L, 10,000 km
B uses 166.7 L less (25 %)
Common uses
- Comparing a car’s figure from another country: km/L in India, L/100 km in Europe, mpg in the US and the UK.
- Reading a US fuel economy label, whose consumption figure is in gallons per 100 miles.
- Choosing between two vehicles by the fuel and money they would use over a year of your driving.
- Checking a figure measured from your own fill-ups against the official one.
Distance per fuel and fuel per distance
km/L and mpg say how far one unit of fuel takes you, so higher is better. L/100 km and gallons per 100 miles say how much fuel a distance takes, so lower is better. One is 100 divided by the other: L/100 km = 100 ÷ km/L, and gallons per 100 miles = 100 ÷ mpg.
Because of that division, equal steps in km/L or mpg do not save equal amounts of fuel. Going from 10 to 20 km/L saves 5 L every 100 km, but going from 20 to 40 km/L saves only 2.5 L more. To see what a better car really saves, compare the fuel per distance — Compare two vehicles does that for any two figures.
US and UK gallons
The US gallon is exactly 231 cubic inches, 3.785411784 L (NIST Handbook 44, Appendix C), and the imperial gallon of the UK is exactly 4.54609 L (NIST SP 811, Appendix B), about 20 % larger. The same car therefore has a higher mpg in UK units: 1 mpg (US) ≈ 1.201 mpg (UK), and 1 mpg (UK) ≈ 0.8327 mpg (US).
With the mile of exactly 1,609.344 m, L/100 km ≈ 235.215 ÷ mpg (US) ≈ 282.481 ÷ mpg (UK). US fuel economy labels also give the consumption in gallons per 100 miles (40 CFR 600.302-12).
CNG, LPG and electric cars
km/kg (CNG or LPG sold by the kilogram) and kWh per 100 km, Wh/km, mi/kWh or MPGe (electric cars) measure different things from litres of liquid fuel: they cannot be converted into km/L or mpg without the energy and price of each fuel, so this page does not offer them. To compare running costs, price each car per kilometre — the Fuel Cost Calculator does that, for petrol, diesel, CNG and electric cars.
Limitations
- A converted figure is only as good as the original: an official test result and your own fill-up measurement can differ a lot.
- Compare two vehicles assumes each keeps the same fuel economy over the whole distance and that both pay the same price.
- Fuel sold by mass (CNG in km/kg) and electricity (kWh/100 km, MPGe) are not converted.
- Results are exact fractions shown to 10 significant digits (marked ≈ when rounded).
Privacy
Everything happens in your browser. What you enter or open here is not uploaded or stored by MySmartCoPilot.
Frequently asked questions
How do I convert km/L to L/100 km?
Divide 100 by the km/L: 15 km/L is 100 ÷ 15 ≈ 6.67 L/100 km. It works the same way back: 5 L/100 km is 100 ÷ 5 = 20 km/L.
How do I convert mpg to L/100 km?
Divide 235.215 by US mpg, or 282.481 by UK mpg: 30 mpg (US) ≈ 7.84 L/100 km, 30 mpg (UK) ≈ 9.42 L/100 km.
Why are UK mpg figures higher than US ones for the same car?
The imperial gallon (4.54609 L) is about 20 % larger than the US gallon (3.785411784 L), so a car goes about 20 % further on one: 30 mpg (US) ≈ 36.03 mpg (UK).
Is a lower L/100 km better?
Yes. L/100 km and gallons per 100 miles are fuel used, so lower is better; km/L and mpg are distance travelled, so higher is better.
Can I convert CNG km/kg or an electric car’s kWh/100 km to km/L?
No — they measure a different fuel, by mass or by electrical energy. Compare the running cost per km instead with the Fuel Cost Calculator, which prices fuel by the litre, kg or kWh.
How much fuel will I save with a more efficient car?
Type both cars into Compare two vehicles with the distance you drive. A car at 20 km/L instead of 15 km/L uses 166.7 L less over 10,000 km; add the fuel price to see the money.