How this calculation works
Temperature conversions need an offset as well as a scale factor. Kelvin begins at absolute zero; values below absolute zero are rejected.
°F = °C × 9/5 + 32; K = °C + 273.15A worked example
0 °C equals 32 °F and 273.15 K.
Good to know
Uses the stated formula and assumptions. Displayed decimal values are rounded; use consistent units for all inputs.
Zero on one temperature scale need not mean no thermal motion
0°C corresponds to 32°F and 273.15 K. Celsius and Fahrenheit have shifted origins, so converting them requires an offset as well as a multiplier. Multiplying 0°C by 9/5 alone would miss the 32-degree offset.
Kelvin begins at absolute zero. That gives absolute-temperature ratios a different meaning from ratios of Celsius readings. Doubling a Celsius number is not generally the same as doubling absolute temperature.
An absolute reading and a temperature change convert differently
A change of 10°C equals a change of 10 K or 18°F. Do not add 32 when converting a temperature difference; that offset belongs to readings on the scales, not to their increments.
This tool converts absolute readings and rejects values below absolute zero. A physical application may have other constraints, such as material phases, that a scale conversion alone cannot evaluate.
A few questions, answered
Why is kelvin written without a degree sign?
The SI unit is kelvin, symbol K. The Celsius and Fahrenheit scales use °C and °F.
Does this tool convert temperature differences?
Its input represents an absolute reading. For differences, use only the appropriate scale factor and no offset.