A Japanese car import is rated 15 km/L. How does that compare to a US car rated 38 mpg?

15 km/L × 2.352 = 35.3 mpg. The US car at 38 mpg is slightly more efficient. Note that Japanese JC08 test conditions can produce optimistic results compared to US EPA methodology, so real-world figures may be closer.

My car's dashboard shows km/L. It's currently reading 13.5. What's that in mpg?

13.5 × 2.352 = 31.8 mpg. That's decent — slightly above the US EPA average for new cars (around 28 mpg combined). Normal for a mid-size petrol car in moderate driving.

Is the multiplication factor 2.352 exact, or is it rounded?

The exact factor is 2.35214583, derived from 1 mile = 1.609344 km and 1 US gallon = 3.785411784 L: (1.609344 ÷ 3.785411784) × 1,000 ÷ 100 ≈ 0.425... wait — the factor is 1 ÷ 0.425 = 2.352. For everyday use, 2.352 is accurate to four significant figures.

km/L to MPG (US) Converter

Enter a value to instantly convert between fuel economy units.

From

Precision4 dp

1 Km per Liter = 2.3521 MPG (US)

Key Formulas

MPG (US) → Liters per 100km

L/100km = mpg × 235.215

Liters per 100km → MPG (US)

mpg = L/100km × 235.215

Km per Liter → MPG (US)

mpg = km/L × 2.35215

MPG (US) → Km per Liter

km/L = mpg × 0.425144

Formula

mpg (US) = km/L × 2.35214583

When you're cross-shopping a Japanese domestic market car against an American EPA-rated vehicle, you need to bridge two 'higher is better' efficiency scales that use different units. Both km/L and mpg measure distance per unit of fuel — the difference is just the length (kilometres vs miles) and the volume (litres vs US gallons). The conversion factor 2.352 accounts for both: multiply km/L by 2.352 to get mpg. The math is straightforward because, unlike L/100km, there's no inversion involved.

Source: US EPA Fuel Economy Methodology

Last reviewed: 2026-06-11 · see our methodology

Frequently Asked Questions

Not directly. Japan's older JC08 test cycle and the newer WLTC cycle both produce different results from the US EPA two-cycle test. Japanese figures tend to be slightly optimistic. When comparing a JC08-rated car to an EPA-rated car, expect the Japanese car's real-world mpg to land 10–15% below the converted figure. For European WLTP comparisons, see [km/L to L/100km](/fuel/kml-to-l-per-100km/).

Real-World Examples

A Honda Fit rated 18 km/L on the Japanese JC08 test converts to 42.3 mpg — competitive with US hybrid EPA ratings.

18 km/L = 42.3 mpg

A typical mid-size Japanese sedan at 10 km/L equals 23.5 mpg, closely matching EPA combined ratings for cars like the Nissan Altima.

10 km/L = 23.5 mpg

A Toyota Land Cruiser rated 7 km/L in the Japanese market sits at 16.5 mpg — typical for large body-on-frame SUVs in the US as well.

7 km/L = 16.5 mpg

A Toyota Prius plug-in hybrid rated 25 km/L on the JC08 combined cycle converts to 58.8 mpg — higher than its US EPA figure due to more optimistic Japanese test conditions.

25 km/L = 58.8 mpg

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km/L to MPG (US) Converter

Key Formulas

Formula

Frequently Asked Questions

Real-World Examples

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