Unit Converter
Convert length, weight, temperature, volume, area, speed, data, pressure and energy, using the exact definition of every unit.
Key facts
- Since 1959 the inch has been exactly 2.54 cm and the pound exactly 0.45359237 kg, so most metric to US conversions are exact.
5 m =
16.4042ft
5 meters is 16.4042 feet.
- 1 m
- 3.2808 ft
- 1 ft
- 0.3048 m
How this works: Method, 3 sources, Checked against 15 worked examples,
How this works
Method
Each unit is stored as its size in its quantity’s base unit, at its exact definition where one exists (the inch is 0.0254 m, the pound 0.45359237 kg), and value in the new unit = value × size of the old unit ÷ size of the new one. Temperature is the one quantity with an offset, converted through kelvin (°F = °C × 9/5 + 32). Answers are shown exactly when they have up to 4 decimals, otherwise to about six significant figures.
Sources
How it’s tested
15 worked examples for this page are checked by automated tests before every release: given the inputs, the tool must show the expected answer.
Privacy
On your device. Nothing you enter or open leaves this browser. Without AI, everything stays on this device. If you added your own AI key, Ask sends your question (or, for Explain my result, the figures) to that provider. Built-in browser AI keeps it here. Until you add your own AI key, nothing can be sent. About privacy labels
Changes
- Ask understands “5 ft 9 in to cm” and “2 cups of flour in grams” and answers at once, and a decimal comma (“2,5”) reads as 2.5.
- First published: 89 everyday units across ten quantities, with 58 pages for common pairs such as cm to inches and Celsius to Fahrenheit.
All 58 conversions
Each with the formula, a chart and a mental shortcutLength12
Volume8
Area5
Cooking2
Frequently Asked Questions
Which units can this converter handle?
Length, weight, temperature, volume, area, speed, data size, data rate, pressure and energy: about a hundred everyday units, from millimeters to miles, ounces to metric tons, teaspoons to UK gallons and kilobytes to tebibytes. Force, power and rarer scientific units are in the Physics Unit Converter.
How accurate are the conversions?
Each unit is stored at its exact legal definition where one exists: the inch is 2.54 cm, the pound 0.45359237 kg, the US gallon 231 cubic inches (3.785411784 L), the standard atmosphere 101,325 Pa. Answers are rounded for reading (six significant figures), and the copy button gives the same figure.
Are fluid ounces, cups and gallons US or UK?
Plain “fl oz”, “cup” and “gallon” are the US units. The UK (imperial) fluid ounce, pint and gallon are listed separately and marked UK; an imperial gallon is about 20% bigger than a US gallon, but an imperial fluid ounce is about 4% smaller than a US one.
Is a megabyte 1000 or 1024 kilobytes?
Officially 1000: the SI prefixes kilo, mega and giga mean 10³, 10⁶ and 10⁹ for bytes too. The 1024-based units have their own names, kibibyte (KiB), mebibyte (MiB) and gibibyte (GiB). Windows still labels 1024-based sizes as KB, MB and GB, which is why a drive looks smaller there than on the box.
Can I share a conversion?
Yes. The address bar always holds the quantity, the two units and the number, so copying the link (or Copy link in the ⋯ menu by the answer) opens the same conversion for anyone.