Unit converter

Type a query in the top box: a number, a unit, to (or in, as), and a target unit.

Compound units: N·m, kg·m^2/s2, km/h, J/(kg·K), BTU/h, L/100 km. Multiply with ·, *, or a space; divide with /; powers with ^2, ², or a glued digit (m2, s-2).
Prefixes: k, M, G, m, µ (or u), n, p … on SI units, and Ki, Mi, Gi on bits and bytes.
Temperatures: °C, °F, K, °R convert as absolute temperatures; inside a compound unit (J/°C) they count as temperature differences.
Reciprocal units convert as inverses (L/100 km ↔ mi/gal), and rotation converts to frequency assuming one cycle is 2π rad (rpm ↔ Hz ↔ rad/s).
Incompatible units are reported with their dimensions, so 1 m to s says length versus time.

Convert to every unit lists a value in all the units of a category; click a row to make it the source. Favourites and the number of significant digits are remembered.

Definitions follow the SI and the international yard and pound (1959). US customary volumes are used for gal, qt, pt, cup, floz; the imperial ones are galUK, ptUK, flozUK. The calorie is the thermochemical calorie (4.184 J); Cal is the food Calorie.

Share link (under the title) copies a URL that reopens this tool exactly as you have it — every tab’s inputs, with the current tab selected. Opening such a link replaces the inputs this browser had saved for the tool.

You can also write a link by hand with the readable parameters v, from, to — for example ?v=60&from=mph&to=km/h. v, from and to fill the converter; q takes a whole query such as 3.5 ft·lbf to N·m.

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