About Measure-ly

Where it came from

I built Measure-ly because I kept getting tripped up comparing electric vehicle charging costs to petrol. The problem wasn't the maths — it was the units. EV efficiency shows up in kWh/100km or mi/kWh depending on the source. Petrol efficiency is L/100km in most of Europe, mpg in the UK and US, and the UK and US use different gallons. Manufacturer specs, fuel price websites, and forum posts all used different units without warning.

There were converters out there, but they were either buried inside larger tools, surrounded by ads, or just slow. I wanted something that loaded instantly, worked offline, and got out of the way. So I built it.

What it is

• Free. No subscription, no paywall, no account required — ever.
• No login. Nothing is saved to a server because there is no server doing anything with your data.
• Fast. Everything runs in the browser. No round-trips to an API for conversion results.
• Fuel & energy focus. The Fuel & Energy section covers all the unit pairs that tripped me up: L/100km, km/L, mpg (US), mpg (UK), kWh/100km, mi/kWh, Wh/km, and MPGe.

Car preset data

The trip cost calculator includes real car presets drawn from official WLTP test-cycle figures published by the European Environment Agency (EEA). WLTP (Worldwide Harmonised Light Vehicle Test Procedure) is the EU's standardised fuel-economy test, used for all new cars sold in Europe since 2019.

Real-world consumption is typically 10–20% higher than WLTP figures. The calculator lets you enter your own measured value if you prefer.

Contact

Questions, corrections, or suggestions — hello [at] measure-ly.com.