Kilometers per liter and miles per US gallon
Kilometers per liter is the distance driven on one liter of fuel. Brazil, India, Japan and much of Latin America and Asia rate cars in km/L.
US miles per gallon is the distance in miles driven on one US gallon (3.785 L). EPA window stickers and car reviews in the US quote mpg.
Worked example
Convert 12 km/L: 12 × 2.352145833 = 28.22575, so 12 kilometers per liter is 28.22575 miles per US gallon. Likewise 16 km/L = 37.63433333 mpg.
Estimating in your head
Multiply by 2.4 for a quick figure; it is off by about 2%. For 12 km/L that gives 28.8 mpg, against 28.2258 exactly.
Going the other way
To convert miles per US gallon to kilometers per liter, divide by 2.352145833 (or multiply by 0.42514370743). The swap button between the boxes opens that page.
How this works
mpg = km/L × 2.352145833
1 km/L = 1 km/L and 1 mpg = ≈ 0.4251437074 km/L, both by definition, so the factor is their ratio: 2.352145833 (rounded here; the page uses the full value). Results drop binary floating-point noise beyond 15 significant digits and display at the precision you choose (6 significant figures by default). Copy result copies the full value.
Frequently asked
How many miles per US gallon are in a kilometer per liter?
1 kilometer per liter = 2.352145833 miles per US gallon. The factor is exact by definition but has endless decimals, so it is shown rounded; the page uses the full value.
How do I convert kilometers per liter to miles per US gallon?
Multiply by 2.352145833. For example, 16 km/L × 2.352145833 = 37.63433333 mpg.
What is 20 km/L in miles per US gallon?
20 km/L = 47.04291667 mpg. The table next to the converter lists more common values.
Is the result rounded?
Only on screen. The page computes with the exact definitions and removes floating-point noise past 15 significant digits; pick 3 to 12 significant figures, or use Copy result for the full value.
Sources
- NIST Handbook 44 — Appendix C, General tables of units of measurement
- UK Weights and Measures Act 1985, Schedule 1 — Definitions of units
- Wikipedia — Fuel economy in automobiles
Reviewed Oct 17, 2026 · test vectors fixtures/units/fuel/km-l-to-mpg/