Is higher L/100km better or worse?

Lower L/100km is better — it means less fuel used over the same distance.

Why is the conversion reciprocal instead of linear?

Because the units encode fuel consumption from opposite directions. mpg measures "distance per unit of fuel" (more is better); L/100km measures "fuel per unit of distance" (less is better). The two are mathematically inversely related, so the conversion is a division, not a multiplication.

Are US and UK gallons the same in mpg calculations?

No — this calculator uses US gallons (1 US gal = 3.785411784 L). A car rated 30 US mpg is rated about 36 UK mpg (1 imperial gal = 4.54609 L). If you need imperial mpg, multiply US mpg by 1.20095.

Unit converter — Fuel consumption

Liters per 100 km to miles per US gallon converter

Convert liters per 100 km (L/100km) to miles per US gallon (mpg). Reciprocal relationship — more fuel used per distance gives lower L/100km.

Results are mathematically exact for the displayed precision. How we calculate.

How it's calculated

Convert liters per 100 km to miles per US gallon— the formula

Fuel consumption is reciprocal — more fuel used per distance means lower liters per 100 km and higher L/100km. The conversion goes through L/100km as a canonical form.

mpg = 235.214583 ÷ (L/100km)

Reciprocal relationship (more fuel = lower mpg = higher L/100km). US mpg ↔ L/100km via 235.214583 = (3.785411784 L/gal × 100 / 1.609344 km/mi). km/L = 100 / L/100km.

Questions

Frequently asked questions

Is higher L/100km better or worse?
Lower L/100km is better — it means less fuel used over the same distance.
Why is the conversion reciprocal instead of linear?
Because the units encode fuel consumption from opposite directions. mpg measures "distance per unit of fuel" (more is better); L/100km measures "fuel per unit of distance" (less is better). The two are mathematically inversely related, so the conversion is a division, not a multiplication.
Are US and UK gallons the same in mpg calculations?
No — this calculator uses US gallons (1 US gal = 3.785411784 L). A car rated 30 US mpg is rated about 36 UK mpg (1 imperial gal = 4.54609 L). If you need imperial mpg, multiply US mpg by 1.20095.