ToolsUnit ConvertersGeneral

Temperature Converter

Convert between Celsius, Fahrenheit, Kelvin, and Rankine. Free online temperature converter for engineers and scientists.

Last updated 19 February 2026

About this tool

Convert between the four main temperature scales: Celsius, Fahrenheit, Kelvin, and Rankine. Enter a value in any field and all other values update automatically.

Temperature scales

Celsius (°C): The metric scale, where water freezes at 0° and boils at 100°. Used worldwide for everyday and scientific purposes.

Fahrenheit (°F): Used primarily in the United States. Water freezes at 32° and boils at 212°.

Kelvin (K): The SI unit for temperature, used in science and engineering. Zero Kelvin is absolute zero (-273.15°C), the coldest possible temperature.

Rankine (°R): An absolute scale like Kelvin, but using Fahrenheit-sized degrees. Used in some US engineering applications, particularly thermodynamics.

Revision history

19 February 2026: Initial release

Disclaimer

This tool is provided for educational and general information purposes only. It is not a substitute for professional engineering advice, design or verification.

Diggy and its contributors are not licensed engineering consultants and no results generated by this tool should be used directly for construction, design or safety-critical decisions.

All values and outputs are based on published empirical correlations and should be independently checked and confirmed by a qualified geotechnical engineer before use.

By using this tool, you accept full responsibility for how you interpret and apply the information provided.

Spotted an error? Let us know.

Temperature

Celsius (°C)

Fahrenheit (°F)

Kelvin (K)

Rankine (°R)

Reference temperatures

0°C

Water freezes

100°C

Water boils

37°C

Body temp

-273.15°C

Absolute zero