Fuel Economy Converter
A fast, private fuel economy converter. Pick your units, type a value, and the conversion appears instantly — in either direction. Everything runs on your device, so nothing you enter is ever uploaded.
- 🔒 100% private — no uploads
- 🆓 Free, no watermark
- 📱 Works on any device
How to convert
- 1
Choose your units
The tool opens on the most common pairing. Change either unit from its dropdown, or hit the swap button to flip the direction.
- 2
Type a value
Enter a number in either box. The other side updates instantly as you type — convert either way without pressing a button.
- 3
Copy or compare
Copy the result to your clipboard, or scan the common-values table below for quick at-a-glance conversions.
Why use Fuel Economy Converter?
100% private
Every conversion is computed locally in your browser. Nothing you enter ever leaves your device.
Instant & two-way
Results update live as you type, in either direction — no “convert” button and no page reloads.
Accurate
Conversions use exact, standards-based factors, so you get the same answer a trusted reference would.
Works on any device
No install and no account — it runs in any modern browser on desktop, tablet or phone.
MPG, L/100km and km/L
Fuel economy has no universal unit: the US uses miles per US gallon, Europe liters per 100 km, and much of Asia kilometers per liter. They measure in opposite directions — more mpg is better, fewer L/100km is better — and the conversion is inverse: L/100km = 235.215 ÷ mpg (US).
The imperial-gallon gotcha
UK mpg uses the imperial gallon (4.546 L), so a UK “50 mpg” equals about 42 mpg US — a 20% difference that makes cars look thriftier in British reviews. When comparing cars across markets, convert everything to L/100km first; it’s the least ambiguous scale.
Frequently asked questions
What units does the fuel economy converter support?
It covers the common fuel economy units (km/L, mpg, mpg UK, L/100km and others). Choose any two from the dropdowns and convert between them instantly.
Does anything get uploaded to a server?
No. The conversion runs entirely in your browser with JavaScript — nothing you type is uploaded, stored or logged, and it keeps working offline once the page has loaded.
Is it free?
Yes — completely free, with no account, no watermark and no limits on how much you convert.