Unit Converter — Length, Weight, Temperature and More
Convert between hundreds of units across eight measurement categories.
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Common conversions
Full conversion table
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Convert length, weight, temperature, data, area, volume, speed and time. Pick a category, choose your units, and the result updates as you type — along with a full table showing the same value in every other unit in that category.
How to use Unit Converter
- Pick a measurement category from the tabs.
- Choose your units and type a value in either box — conversion works in both directions.
- Use the swap button to reverse the direction.
- Check the full table below for every other unit at once.
How the conversions work
Every category has a base unit — the metre for length, the kilogram for weight, the second for time. Converting means moving the value into the base unit and back out into the target: base = value × factor + offset, then target = (base − offset) ÷ factor.
The offset term exists for temperature, which is an interval scale rather than a ratio scale. 20 °C is not "twice as hot" as 10 °C, because the zero point is arbitrary — which is exactly why temperature needs the extra term and everything else does not.
Kilobytes vs kibibytes
In the data category you will find both. A kilobyte (KB) is 1,000 bytes; a kibibyte (KiB) is 1,024. Storage manufacturers use the decimal units, while operating systems have historically reported the binary ones — which is why a "1 TB" drive shows up as about 931 GB in Windows. Nothing is missing; the two are just counting differently.
US and UK measures are not the same
A US gallon is 3.785 litres; a UK (imperial) gallon is 4.546 — about 20% larger. US and UK fluid ounces differ too. Both are listed separately here, because assuming they are interchangeable is a common and expensive mistake in recipes and fuel calculations alike.
Frequently asked questions
What is the difference between KB and KiB?
A kilobyte (KB) is 1,000 bytes; a kibibyte (KiB) is 1,024. Drive manufacturers use decimal units while operating systems have historically reported binary ones — which is why a "1 TB" drive shows as about 931 GB. Nothing is missing, they are just counting differently.
Is a US gallon the same as a UK gallon?
No. A US gallon is 3.785 litres, a UK imperial gallon is 4.546 — about 20% larger. US and UK fluid ounces differ too. Both are listed separately here.
Why does temperature convert differently?
Temperature is an interval scale, not a ratio scale — its zero point is arbitrary, so 20 °C is not twice as hot as 10 °C. That means conversion needs an offset as well as a multiplier. Every other category is a simple ratio.
How accurate are the conversions?
Factors are stored to 15 decimal places and use exact internationally defined values where they exist — an inch is exactly 0.0254 m, a pound exactly 0.45359237 kg. Results are shown to about 8 significant figures.