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Metric ⇄ Imperial Unit Converter

Switch between metric and imperial measurements in real time.

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Frequently asked questions

Which countries still use imperial units?

Only the United States, Liberia and Myanmar use it as the primary system. The UK is genuinely mixed — road distances are in miles and beer in pints, but most other measurements are metric, which is why conversion comes up so often there.

Why is temperature not a simple multiplication?

Because Celsius and Fahrenheit have different zero points as well as different scale sizes, so you need both an offset and a factor: F = C x 9/5 + 32. Most other conversions are a single multiplication.

What is the difference between a US and an imperial gallon?

They are genuinely different: a US gallon is about 3.79 litres, an imperial gallon about 4.55. That is a 20% gap, which catches people out in recipes and fuel-economy figures alike.

Pro tips

  • Read the whole column rather than one target. Seeing a value in every unit at once is how you catch a conversion that is out by a factor of ten.
  • Check which system a recipe was written for before converting volumes; US and imperial cups and ounces are not the same measure.
  • Convert differences and absolute values separately for temperature — only absolute values take the offset.
  • Do not carry more decimal places than your input justifies. Converting a measurement made to the nearest centimetre into four decimal places of inches invents precision.
  • When a value crosses a boundary between teams or systems, write the unit next to it. Unit ambiguity, not arithmetic, is what loses spacecraft.

About Metrics & Unit Converter

Every equivalent updates at once rather than one target at a time, so a single value can be read across all its units together — useful against a recipe, a spec sheet, or instructions written for another country's conventions.

Convert between metric and imperial units — centimetres to inches, kilograms to pounds, Celsius to Fahrenheit and many more — with every equivalent updating as you type. All maths runs locally.

Convert length, weight, temperature, volume, speed and many other units instantly. Type a value and every equivalent updates in real time, so you can move between metric and imperial — centimetres to inches, kilograms to pounds, Celsius to Fahrenheit — without doing the maths.

It covers cooking, travel, DIY, science homework and engineering from one panel. Temperature is the conversion that catches people, because it shifts by an offset as well as a scale — 0 °C is 32 °F, not 0 °F.

Most conversions are a single multiplication, and the ones that are not cause most of the errors. Temperature carries an offset as well as a scale because its scales do not share a zero, which means a temperature and a temperature difference convert differently: a rise of 10 °C is a rise of 18 °F, not 50 °F. Applying the full formula to a difference is a mistake that survives into published copy regularly.

Two more traps are worth naming. A US fluid ounce and a UK fluid ounce differ by about four percent, which is invisible in a drink and ruinous in baking. And digital storage is quoted two ways — drive manufacturers count a gigabyte as 1,000,000,000 bytes while operating systems often report binary gibibytes — which is the entire reason a 1 TB drive shows up as roughly 931 GB with nothing missing.

Common use cases

  • Following a recipe written for the other measurement system
  • Converting product dimensions before ordering from abroad
  • Making sense of distances and weights while travelling
How it comparesSearch engines convert a single pair inline and stop there. A dedicated panel is worth opening when you have several values to move, or when you want every equivalent visible at once rather than asking one question at a time.