Unit Converter
Pick a group, type a number and choose the units. Every conversion uses the exact official definition.
Step by step
Your previous calculations
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How it works
The method
Every unit is an exact amount of a base unit, fixed by international agreement: 1 inch = 2.54 cm, 1 pound = 0.45359237 kg, 1 US gallon = 231 cubic inches. A conversion multiplies by one size and divides by the other.
Worked example
5 feet = 5 × 12 × 2.54 cm = 152.4 cm. 100 °F in °C: (100 − 32) × 5 ÷ 9 = 37.7̅ °C.
Common mistakes
Temperatures need an offset, not only a multiplier. US and UK gallons, pints and fluid ounces are different sizes.
Questions & answers
Why is the answer empty?
Type a number in Value and choose both units. Use your language's decimal mark (1.5 or 1,5) and no letters or unit signs in the box.
Why does a … appear at the end of some answers?
Some conversions never end as a decimal, like 1 hectare = 2.47105381467… acres. Every digit shown is correct and … means more digits follow; nothing is rounded. The exact value is also shown as a fraction.
Why is my 1 TB drive shown as 931 GB on my computer?
Drive makers count 1 TB = 1,000,000,000,000 bytes. Many computers count in powers of 1024 (GiB): 1 TB = 931.32257461… GiB. Choose GiB, MiB or KiB in To to see the computer's number.
Which gallon, cup and ton are used?
Both gallons are in the list: US gallon = 3.785411784 L and UK gallon = 4.54609 L. Cup, pint, tablespoon and teaspoon are US measures. For tons, pick tonne (1000 kg), short ton (US, 2000 lb) or long ton (UK, 2240 lb).
How do I convert a temperature?
Open Temperature, type the number and choose °C, °F or K. 98.6 °F = 37 °C and 0 °F = −17.7̅ °C (the 7 repeats). The steps show how it was worked out.
What is a decimal (land unit)?
A decimal is 1/100 of an acre = 40.468564224 m² = 435.6 ft², used for land in Bangladesh and India. Local units like katha and bigha are not listed because their size differs from place to place.