Unit Converter: Length, Mass, Volume, Energy and More
Which unit converter do you need?
Pick the converter for the quantity you are measuring. Length, area, volume, mass, temperature, time, energy, power, pressure and the rest each have their own page, because a unit only converts inside its own dimension.
Start from the shortlist if the quantity is one readers reach for most, or from the grid below if it is not. Each converter carries its own factor table and its own worked conversion.
Where Most Readers Start
- convert an angle between degrees and radians
- convert power between watts and horsepower
- convert a flow rate between litres per minute and cubic metres per second
Every Converter in This Family
One row per converter, with the quantity it measures and the SI unit that quantity is held in. The electrical quantities are read together, so they share a page one level down.
| Quantity | SI unit | Converter |
|---|---|---|
| angle | radian | Angle units |
| area | square metre | Area units |
| digital storage | byte | Digital storage units |
| count | each | Count units |
| the electrical quantities | its own units | the electrical quantities in one place |
| energy | joule | Energy units |
| frequency | hertz | Frequency units |
| illuminance | lux | Illuminance units |
| length | metre | Length units |
| pace | second per metre | Pace units |
| parts-per ratio | one (dimensionless) | Parts-per units |
| power | watt | Power units |
| pressure | pascal | Pressure units |
| speed | metre per second | Speed units |
| temperature | kelvin | Temperature units |
| time | second | Time units |
| torque | newton metre | Torque units |
| unit conversion | any unit | factors, dimensions and SI prefixes |
| volume | cubic metre | Volume units |
| volumetric flow rate | cubic metre per second | Flow rate units |
| mass | kilogram | Weight and mass units |
How This Family Is Organised
The figures below are the knowledge base's own. The grid above lists this hub's direct children, which is fewer than the family's tool count because the electrical quantities have a page of their own.
Units only convert inside their own dimension. A length converts to a length and a mass converts to a mass, which is why each measurement family has its own converter.
A conversion factor is a ratio equal to one. Because 1 in = 25.4 mm, the ratio 25.4 mm / 1 in equals one, and multiplying by it changes the unit without changing the quantity.
- Unit Converter hub, tool link count 25
- unit-conversion family, live url count 28
- Unit Converter hub, dimension groups geometry; mechanics; time-rate; energy-power; electrical; ratio-count; thermal-light
Which Converter Do I Need?
Pick the converter for the quantity being measured rather than for the unit in front of you: a value in millimetres and a value in miles belong on the same page, and a value in kilograms belongs on a different one. Where two quantities share a dimension, such as torque and energy, they still have separate pages, because the units are not interchangeable.
Guides
Frequently Asked Questions
What is a unit converter?
A page that rewrites a measured value in a different unit of the same quantity. It multiplies by the factor between the two units, so the amount stays the same and only the unit it is counted in changes.
Can you convert a length into a weight?
No. Units convert only inside their own dimension, so a length converts to a length and a mass to a mass. Crossing between them needs a physical property such as density, which is a calculation rather than a conversion.
Is a unit converter the same as a calculator?
No. A converter rewrites one value in another unit of the same quantity. A calculator combines several values into a new quantity, which is a different job with a different kind of answer.
Which converter handles the electrical units?
The electrical unit converter groups current, voltage, charge, reactive power, apparent power and reactive energy, because those quantities are read together and share a set of prefixes.