Does it handle heights written as feet and inches?

Both feet and inches appear in the length table, so enter 5 foot 10 as 70 inches. There is no combined feet-and-inches input field. One foot is twelve inches.

How many millilitres is "one cup"?

It depends on the country: 200 mL in Japan, about 236.6 mL in the US, about 284 mL in the UK. Mixing a Japanese recipe with a foreign one drifts by nearly 20%, so convert to millilitres in the volume table first. Japan's "1 go" is 180 mL and is a different measure again from the rice cup.

Can it convert currency?

No. Exchange rates change constantly and would have to be fetched from somewhere, and this tool is built not to talk to anything. Unit conversions are fixed physical ratios, so they can be exact without any network access.

Are the values I enter stored?

No, and nothing is sent. The arithmetic happens entirely in the page.

Temperature is the one that is not a multiplication

Other units are proportional — one inch is 2.54 cm — but temperature scales have different zero points: F = C x 9/5 + 32, with an addition in it. So while 40C is twice 20C as a number, it is not twice as many Fahrenheit degrees (68F doubled is 136F, but 40C is 104F). When converting a temperature difference rather than a temperature, apply the 9/5 without the +32.

Imperial units that share a name but not a size

A US gallon (about 3.785 L) and an imperial gallon (about 4.546 L) differ by a fifth. An ounce is either the avoirdupois ounce of weight (about 28.35 g) or a fluid ounce of volume (about 29.57 mL in the US), and the name alone does not decide. When reading a foreign recipe or specification, establish which system it uses first. Units that need distinguishing are named apart in the tables here.

Significant figures follow the input

The table prints plenty of digits, but that does not mean the original measurement had that precision. Writing "3 inches" as 7.62 cm looks more precise than it is; if the three came off a ruler, 7.6 cm is the honest figure. Round to the precision of the original measurement when writing it up.

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Unit Converter

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Enter one value and see it in every unit of the same kind: inches and centimetres, tsubo and square metres, go and millilitres, °F and °C, GB and GiB. Traditional Japanese units included.

Input

Kind

Value

Unit

Output

The same amount in other units
1,000	millimetre (mm)
100	centimetre (cm)
1	metre (m)
0.001	kilometre (km)
39.370079	inch (in)
3.2808399	foot (ft)
1.0936133	yard (yd)
0.00062137119	mile (mi)
33	sun (Japanese)
3.3	shaku (Japanese)
0.55	ken (Japanese)
0.00025462963	ri (Japanese)

Enter one value and every unit of the same kind appears at once, so you do not have to know the name of the unit you are looking for before you start.

Or type what you want to work out

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Why this one

No need to choose a target unit: Enter one value with its unit and every unit of the same kind appears as a table. A tool built around "inches to centimetres" requires you to already know the name of the unit you want. A table lets you find it by the number instead.
Traditional Japanese units included: Tsubo, jo, go, sho, shaku, sun, kan. They remain in daily use in property listings, sake labelling and timber sizing, and their ratios to metric units are awkward enough that nobody does them in their head. They sit in the same length, area and volume tables as everything else.
GB and GiB are kept apart: Storage is sold in decimal units (1 GB = 1,000,000,000 bytes) while operating systems often count in binary ones (1 GiB = 1,073,741,824 bytes). "I bought a 1TB disk and it says 931GB" is exactly that gap. Both appear in the table, so you can work out which counting a number came from.

How to use

Choose a kind
Length, mass, area, volume, temperature, speed or data.
Enter a value and a unit
Everything else of the same kind is computed from what you entered.
Read the table
"Copy table" takes the whole thing, which pastes into a document as a ready-made conversion table.

Good to know

Temperature is the one that is not a multiplication: Other units are proportional — one inch is 2.54 cm — but temperature scales have different zero points: F = C x 9/5 + 32, with an addition in it. So while 40C is twice 20C as a number, it is not twice as many Fahrenheit degrees (68F doubled is 136F, but 40C is 104F). When converting a temperature difference rather than a temperature, apply the 9/5 without the +32.
Tsubo and square metres: One tsubo is exactly 400/121 square metres, about 3.30578. It does not divide evenly, so property listings round it and different documents end up with slightly different figures. Working backwards with "1 tsubo = 3.3" drifts by nearly a whole square metre over 100 tsubo. Tatami sizes vary by region (Kyoma, Chukyoma, Edoma), and "1 tsubo = 2 tatami" is a rule of thumb rather than a definition.
Imperial units that share a name but not a size: A US gallon (about 3.785 L) and an imperial gallon (about 4.546 L) differ by a fifth. An ounce is either the avoirdupois ounce of weight (about 28.35 g) or a fluid ounce of volume (about 29.57 mL in the US), and the name alone does not decide. When reading a foreign recipe or specification, establish which system it uses first. Units that need distinguishing are named apart in the tables here.
Significant figures follow the input: The table prints plenty of digits, but that does not mean the original measurement had that precision. Writing "3 inches" as 7.62 cm looks more precise than it is; if the three came off a ruler, 7.6 cm is the honest figure. Round to the precision of the original measurement when writing it up.

FAQ

Does it handle heights written as feet and inches?: Both feet and inches appear in the length table, so enter 5 foot 10 as 70 inches. There is no combined feet-and-inches input field. One foot is twelve inches.
How many millilitres is "one cup"?: It depends on the country: 200 mL in Japan, about 236.6 mL in the US, about 284 mL in the UK. Mixing a Japanese recipe with a foreign one drifts by nearly 20%, so convert to millilitres in the volume table first. Japan's "1 go" is 180 mL and is a different measure again from the rice cup.
Can it convert currency?: No. Exchange rates change constantly and would have to be fetched from somewhere, and this tool is built not to talk to anything. Unit conversions are fixed physical ratios, so they can be exact without any network access.
Are the values I enter stored?: No, and nothing is sent. The arithmetic happens entirely in the page.

Input

Output

Related tools

Why this one

How to use

Choose a kind

Enter a value and a unit

Read the table

Good to know

FAQ