Unit converter
Convert length, weight, temperature, speed, area, volume, time and data in one place. Type a value in any unit and every other unit updates instantly, all in your browser.
Files are processed in your browser and never uploaded.
How to use Unit converter
Enter your figures
Fill in Metre m, Kilometre km, Centimetre cm and Millimetre mm. Values you change are used straight away, with no submit button.
Adjust the assumptions
Fine-tune Mile mi, Yard yd, Foot ft and Inch in to match your own situation.
Read the results
The totals and the breakdown below them update as soon as a value changes.
What this tool does
Eight categories from length to data size
Length, weight, temperature, speed, area, volume, time and data size are all here, so one page covers most conversions.
Type any value and all units update at once
Type a value into any unit and every other unit in that category updates at once, so you never pick a direction.
Mixes metric, US and imperial units
Metric, US customary and imperial units sit side by side, which is the point when a US gallon and an imperial one differ.
Accurate, standard conversion factors
The factors are the standard definitions rather than rounded approximations, so a chain of conversions does not drift.
Runs in your browser, nothing uploaded
Everything is arithmetic done in your browser, so nothing is uploaded and it works with no connection.
Frequently asked questions
Is anything uploaded or saved?
No. Every conversion is simple maths done instantly in your browser. Nothing you type is sent anywhere or stored.
What can it convert?
Length, weight, temperature, speed, area, volume, time and data sizes. Pick a category at the top, type a value in any unit, and all the other units update at once.
How accurate are the conversions?
They use standard internationally agreed factors, so they are accurate for everyday and most professional use. Results are shown to several significant figures.
Does it handle US and metric units together?
Yes. Each category mixes metric and US or imperial units, such as miles with kilometres or US gallons with litres, so you can convert straight between them.
Why are temperatures handled differently?
Temperature scales have different starting points, not just different sizes, so Celsius, Fahrenheit and Kelvin are converted with their proper formulas rather than a single multiplier.
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