Fuel Economy converter
Miles per Gallon (US) to Kilometers per Liter
Miles per Gallon (US) and Kilometers per Liter measure the same quantity in different unit systems. The relationship is 1 mpg = 0.42514371 km/L, which gives 0.42514371 km/L per mpg. Below you can convert any value, check a worked example and read the full chart.
Formula 1 mpg = 0.42514371 km/L
Need the other direction? Kilometers per Liter to Miles per Gallon (US).
How to convert Miles per Gallon (US) to Kilometers per Liter
US miles per gallon equals about 0.425 km/L; the UK gallon is larger. Kilometres per litre is a direct fuel-economy measure used in many markets.
To convert Miles per Gallon (US) to Kilometers per Liter, multiply the value in mpg by 0.42514371. For example, 10 mpg × 0.42514371 = 4.251437 km/L. This works because the ratio between the two units is constant for every value in fuel economy.
Worked examples
| mpg | km/L |
|---|---|
| 1 mpg | 0.42514371 km/L |
| 2.5 mpg | 1.062859 km/L |
| 5 mpg | 2.125719 km/L |
| 10 mpg | 4.251437 km/L |
| 25 mpg | 10.628593 km/L |
| 50 mpg | 21.257185 km/L |
| 100 mpg | 42.514371 km/L |
Reverse conversion
| km/L | mpg |
|---|---|
| 1 km/L | 2.352146 mpg |
| 5 km/L | 11.760729 mpg |
| 10 km/L | 23.521458 mpg |
| 25 km/L | 58.803646 mpg |
| 50 km/L | 117.607292 mpg |
| 100 km/L | 235.214584 mpg |
When this conversion is useful
This is the calculation you need when you are comparing a car's consumption with a different unit system. Because the factor is fixed, you can use the same number for a single measurement or for a batch: 1,000 mpg is 425.143707 km/L.
Is the conversion exact?
No: fuel economy has inverse units. Litres per 100 km and gallons per mile fall as efficiency rises, so the conversion divides rather than multiplies.
Reference: BIPM SI Brochure and NIST SP 811. Last reviewed: 2026-11-01.
mpg to km/L conversion chart
The chart lists the most requested values. For a value that is not here, use the converter at the top of the page.
| Miles per Gallon (US) (mpg) | Kilometers per Liter (km/L) |
|---|---|
| 1 mpg | 0.42514371 km/L |
| 2 mpg | 0.85028741 km/L |
| 3 mpg | 1.275431 km/L |
| 4 mpg | 1.700575 km/L |
| 5 mpg | 2.125719 km/L |
| 6 mpg | 2.550862 km/L |
| 7 mpg | 2.976006 km/L |
| 8 mpg | 3.40115 km/L |
| 9 mpg | 3.826293 km/L |
| 10 mpg | 4.251437 km/L |
| 11 mpg | 4.676581 km/L |
| 12 mpg | 5.101724 km/L |
| 13 mpg | 5.526868 km/L |
| 14 mpg | 5.952012 km/L |
| 15 mpg | 6.377156 km/L |
| 16 mpg | 6.802299 km/L |
| 17 mpg | 7.227443 km/L |
| 18 mpg | 7.652587 km/L |
| 19 mpg | 8.07773 km/L |
| 20 mpg | 8.502874 km/L |
| 21 mpg | 8.928018 km/L |
| 22 mpg | 9.353162 km/L |
| 23 mpg | 9.778305 km/L |
| 24 mpg | 10.203449 km/L |
| 25 mpg | 10.628593 km/L |
| 26 mpg | 11.053736 km/L |
| 27 mpg | 11.47888 km/L |
| 28 mpg | 11.904024 km/L |
| 29 mpg | 12.329168 km/L |
| 30 mpg | 12.754311 km/L |
| 31 mpg | 13.179455 km/L |
| 32 mpg | 13.604599 km/L |
| 33 mpg | 14.029742 km/L |
| 34 mpg | 14.454886 km/L |
| 35 mpg | 14.88003 km/L |
| 36 mpg | 15.305173 km/L |
| 37 mpg | 15.730317 km/L |
| 38 mpg | 16.155461 km/L |
| 39 mpg | 16.580605 km/L |
| 40 mpg | 17.005748 km/L |
| 41 mpg | 17.430892 km/L |
| 42 mpg | 17.856036 km/L |
| 43 mpg | 18.281179 km/L |
| 44 mpg | 18.706323 km/L |
| 45 mpg | 19.131467 km/L |
| 46 mpg | 19.556611 km/L |
| 47 mpg | 19.981754 km/L |
| 48 mpg | 20.406898 km/L |
| 49 mpg | 20.832042 km/L |
| 50 mpg | 21.257185 km/L |
| 60 mpg | 25.508622 km/L |
| 70 mpg | 29.760059 km/L |
| 80 mpg | 34.011497 km/L |
| 90 mpg | 38.262934 km/L |
| 100 mpg | 42.514371 km/L |
Frequently asked questions
How many Kilometers per Liter are in 1 Miles per Gallon (US)?
1 mpg equals 0.42514371 km/L.
How do I convert Miles per Gallon (US) to Kilometers per Liter?
Multiply the mpg value by 0.42514371. Example: 25 mpg = 10.628593 km/L.
What is 2.5 mpg in km/L?
2.5 mpg = 1.062859 km/L.
Is the mpg to km/L conversion exact?
No: fuel economy has inverse units. Litres per 100 km and gallons per mile fall as efficiency rises, so the conversion divides rather than multiplies.
Does the calculator work offline?
Yes. The conversion runs in your browser with JavaScript, so it works after the page has loaded, even without a connection.