Convert between Celsius, Fahrenheit, Kelvin and Rankine. These scales differ in where zero sits, not only in step size.

How Unit Conversion Works
What is Unit Conversion?

Unit conversion expresses the same physical quantity in a different unit of measure. A length stays the length it was; only the number and the label change, because each unit is defined as a fixed multiple of the same underlying quantity.

Every value here is converted through a base unit: the input is multiplied by its factor to reach the base, then divided by the target factor. Two steps, so a category with fifteen units needs fifteen numbers rather than two hundred pairs.

How to Use
  • Pick a category first. The unit lists and the reference table below both follow the category you select.
  • Type into either field. Both are editable, so the conversion runs in whichever direction you are working, and it updates live with no button to press.
  • Use Swap to turn the conversion around. The values move with their units, so the equation on screen stays true.
  • Copy puts the plain result on the clipboard, without a thousands separator, so it can be pasted straight into a spreadsheet or a shell.
  • The line under the field shows the formula that was applied, so the conversion can be checked by hand.
Temperature is different

Temperature scales have different zero points, so a single factor cannot express them. Celsius, Fahrenheit, Kelvin and Rankine are converted through Celsius with an offset as well as a ratio, which is why 0 °C is 32 °F rather than 0 °F.

Binary against decimal
  • A kibibyte is 1024 bytes, a kilobyte is 1000. Both are offered, because storage vendors and operating systems disagree about which one they mean.
  • Data rates are based on bits, storage on bytes. That factor of eight is why a 1 Gbps line downloads at about 125 MB/s.
Precision

Results are shown to six significant digits, switching to exponential notation beyond a million or below a thousandth. Calculations use double-precision floating point, so a conversion chained through several units can drift in the last digits.

Privacy & Security: the conversion runs entirely in your browser. Nothing you type is sent anywhere, and the tool works with the network disconnected.

Enter a value in either field

Reference

4 units
UnitTypeCommon use
Celsius (°C) metric Weather, cooking (metric)
Fahrenheit (°F) imperial Weather, cooking (US)
Kelvin (K) scientific Scientific calculations
Rankine (°R) scientific Engineering calculations