MPG to L/100km Converter
Convert mpg to l/100km — and back — in an instant. Type a value in either box and the answer updates live. It’s accurate, free and completely private: the conversion runs entirely on your device.
- 🔒 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 MPG to L/100km 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 to L/100km — an inverse relationship
The two scales measure opposite things: mpg counts distance per fuel, L/100km counts fuel per distance. The conversion is L/100km = 235.215 ÷ mpg. So 30 mpg is 7.84 L/100km, and 50 mpg is 4.70 L/100km. Because it’s an inverse, higher mpg means a lower L/100km — better economy on both scales.
What counts as good fuel economy
Roughly: 6 L/100km (39 mpg) is an efficient petrol car, 8 L/100km (29 mpg) a typical one, and 12 L/100km (20 mpg) a thirsty SUV. Note these are US gallons; UK mpg figures use the bigger imperial gallon, so a “50 mpg” UK car is about 42 mpg US.
Frequently asked questions
How do I convert mpg to l/100km?
Type the number of mpg in the first box and read the result in l/100km — it updates as you type. To go the other way, type in the l/100km box instead.
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, no account, no watermark and no limits.