How to Convert Temperature Values Between Units
Enter a temperature, choose its source and target units, and run the conversion. The tool supports Celsius, Fahrenheit, Kelvin, Rankine, and Reaumur, and a successful result also provides values in all five units.
What the temperature converter does
Use this temperature converter when you need to change a numeric reading between Celsius, Fahrenheit, Kelvin, Rankine, and Reaumur. It is useful for checking a value in a different temperature scale or comparing readings that use different units. Choose the unit attached to your starting value and the unit you want for the result, then review the converted output.
How to convert a temperature
- Enter a numeric temperature in the value field. The input is optional: if you leave it empty, the converter uses 0.
- Choose the source unit, meaning the unit of the value you entered. The default source unit is Celsius.
- Choose the target unit, meaning the unit you want to receive. The default target unit is Fahrenheit.
- Run the conversion.
- Review the requested conversion and the additional converted values. A successful result includes values for Celsius, Fahrenheit, Kelvin, Rankine, and Reaumur, so you can compare the same temperature across the supported scales.
If the interface accepts an alternate text value, it is used when the numeric input is falsy and the alternate text is not empty. The converter attempts to read that text as a floating-point number. If the text cannot be parsed, that branch uses 0. Unit names are recognized without regard to capitalization, so capitalization does not affect validation. For predictable results, enter a numeric value and select supported source and target units.
How to read the result
The main result represents the temperature expressed in your selected target unit. For supported units and a value suitable for arithmetic, the converted value is rounded to 10 decimal places. The broader result can also show the equivalent value in each of the five supported units, which helps when you need more than one comparison.
Treat the supported-unit list as the boundary of this converter: Celsius, Fahrenheit, Kelvin, Rankine, and Reaumur. A source or target unit supplied as a string outside that list produces an unsuccessful result. A non-string unit value can fail during unit normalization instead. A nonnumeric temperature that is not successfully replaced through alternate text may fail during calculation, while an unparseable alternate text value follows the fallback behavior described above.
Worked example
You have a reading recorded as 25 degrees Celsius and need to review its Fahrenheit equivalent along with the other supported temperature values.
Enter 25 as the temperature, select Celsius as the source unit, select Fahrenheit as the target unit, and run the conversion.
A successful result contains the requested Fahrenheit conversion rounded to 10 decimal places and converted values for Celsius, Fahrenheit, Kelvin, Rankine, and Reaumur. For the 25 degrees Celsius input, the conversion yields 77 degrees Fahrenheit, with the companion readings 298.15 Kelvin, 536.67 degrees Rankine, and 20 degrees Reaumur.
Limitations
- The converter is limited to five named temperature units. Unsupported unit strings can produce an unsuccessful result, and unsuitable numeric values may fail during calculation.
Common errors
- Using a unit name outside the five supported choices can produce an unsuccessful result. Select Celsius, Fahrenheit, Kelvin, Rankine, or Reaumur; capitalization is not important, but the unit must be one of those supported values.
FAQ
What happens if I leave the temperature field empty?
The numeric input is optional and defaults to 0. The default source is Celsius, and the default target is Fahrenheit, so change those selections when they do not match your value.
Do unit names have to use a specific capitalization?
Yes, capitalization does not affect recognition of a supported unit name because source and target unit names are normalized before validation. The name still needs to be Celsius, Fahrenheit, Kelvin, Rankine, or Reaumur.
How many converted temperature values can the result include?
A successful calculation provides the requested conversion rounded to 10 decimal places and also provides converted values for all five supported units.