Temperature Converter
Convert temperatures among Fahrenheit, Celsius, kelvin, and Rankine. The result includes every scale so you can compare weather readings, laboratory values, or equipment specifications.
Temperature Converter tool
About the Temperature Converter
Unlike length and mass conversions, temperature scales can include an offset as well as a multiplier. The calculator rejects temperatures below absolute zero instead of displaying physically invalid values.
How Is Temperature Calculated?
Use the dimensions and definitions below. Calculations use unrounded intermediate values; displayed results are rounded.
C = (F − 32) × 5 ÷ 9
K = C + 273.15
Rankine = K × 9 ÷ 5
Example
212°F corresponds to (212 − 32) × 5 ÷ 9 = 100°C at the same temperature.
How to Use the Temperature Converter
- Enter a temperature reading.
- Choose its original scale.
- Choose the desired scale.
- Check that the value is not below absolute zero.
- Read the converted value and all-scales table.
Temperature Converter Examples
Boiling point conversion
212°F corresponds to (212 − 32) × 5 ÷ 9 = 100°C at the same temperature.
Freezing point conversion
0°C = 273.15 K = 32°F = 491.67°R.
Measurement and input conventions
Absolute zero is 0 K, −273.15°C, −459.67°F, or 0°R.
For ordinary thermodynamic temperature conversion, values below absolute zero are outside the supported physical range.
Using the result responsibly
No. Water’s boiling temperature depends on pressure. The conversion itself does not depend on the substance.
Keep adequate precision when transferring results to another calculation. Rounding a displayed result too early can change a later answer.
Frequently Asked Questions
What is absolute zero?
Absolute zero is 0 K, −273.15°C, −459.67°F, or 0°R.
Why are negative kelvin values rejected?
For ordinary thermodynamic temperature conversion, values below absolute zero are outside the supported physical range.
Is kelvin written with a degree symbol?
No. Use K for kelvin; Celsius, Fahrenheit, and Rankine use degree symbols.
Can I convert a temperature difference?
This form converts absolute readings. For differences, omit scale offsets: a 1°C change equals a 1.8°F change.
Does 100°C always mean water boils?
No. Water’s boiling temperature depends on pressure. The conversion itself does not depend on the substance.