Fuel Economy Converter
Convert MPG, L/100km and km/L.
✓ Professional standard Uses precise SI and internationally agreed conversion factors for accurate, standards-based results.
Fuel Economy Converter is a free online converter from Toolinza. Convert MPG, L/100km and km/L. It runs entirely in your browser — your data is never uploaded — needs no signup, and works on any device. Toolinza offers 293+ free tools used by people across the UK, USA, Canada, Australia, the EU, India, Pakistan, the Middle East and worldwide.
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About the Fuel Economy Converter
Fuel economy is quoted as miles per gallon in the UK and US, litres per 100 km across Europe, and km per litre elsewhere — which makes comparing cars across markets genuinely confusing. Converting correctly shows which car is actually more efficient.
This Fuel Economy Converter switches between MPG, L/100km and km/L, handling the inverse relationship between them, so comparisons are fair.
How to use the Fuel Economy Converter
- Enter the fuel economy value.
- Choose the unit you are converting from.
- Choose the unit you are converting to.
- Read the converted economy instantly.
Key features of the Fuel Economy Converter
- Converts MPG, L/100km and km/L
- Handles the inverse relationship correctly
- Compares cars across markets
- US and imperial gallons supported
- Private — calculated in your browser
How the Fuel Economy Converter works
Every conversion uses the exact, internationally agreed factors defined by the International System of Units (SI) and recognised standards bodies. Temperature conversions apply the correct formulas rather than simple multipliers, and results retain full precision so they are suitable for scientific, engineering and everyday use alike.
All conversions are calculated instantly in your browser.
Tips & best practices
- L/100km works in reverse to MPG — a lower L/100km is better, while a higher MPG is better.
- Check whether an MPG figure is US or imperial, as UK gallons are larger and give higher numbers.
- For trip costs, convert to your local unit first, then multiply by distance and fuel price.
Standards & accuracy
Uses precise SI and internationally agreed conversion factors for accurate, standards-based results.
Results are accurate to standard conversion factors. For everyday use you can round sensibly; for scientific, medical or engineering work, keep the full precision the tool provides.
Who uses the Fuel Economy Converter?
- Comparing car fuel economy across countries
- Understanding a foreign spec sheet
- Estimating fuel costs for a trip
- Choosing a more efficient vehicle
Privacy & security
The Fuel Economy Converter runs entirely inside your web browser. Your data — whether that is a file, figures or text — is processed on your own device and is never uploaded to a server, stored or shared. There is no signup and no account, so you can use it as often as you like while keeping full control of your information. This makes it a safe choice even for confidential and sensitive work.
Why choose Toolinza?
- 100% free — no hidden charges, watermarks or usage caps.
- Private & secure — your data stays on your device.
- Standards-compliant — accurate results suitable for the UK, USA, Canada, Australia, EU, India, Pakistan, the Middle East and worldwide.
- Works everywhere — desktop, tablet and mobile.
Frequently asked questions
The two are inversely related, so the calculation is not a simple multiply. The converter handles the maths, remembering that lower L/100km means better economy.
No. UK (imperial) gallons are larger than US gallons, so the same car shows a higher MPG figure in the UK. Choose the correct gallon.
Higher is better for MPG and km/L, but lower is better for L/100km, because it measures fuel used per distance.
Yes. The Fuel Economy Converter is completely free with no signup, no watermarks and no usage limits. Toolinza is supported by unobtrusive advertising so every tool stays free.
Absolutely. This tool runs entirely in your browser — your data and files are never uploaded to any server, so everything stays private on your own device.
No. The Fuel Economy Converter works instantly in any modern web browser on desktop, tablet and mobile — Windows, macOS, Linux, Android and iOS.