How to use Temperature Converter
- Enter a temperature reading, including a minus sign if needed.
- Select Celsius, Fahrenheit, or Kelvin as the starting and target scales.
- Read the live answer. A message explains readings below absolute zero instead of showing a misleading result.
A closer look
Temperature scales have different zero points, so conversion requires an offset as well as a scale factor. Celsius to Fahrenheit is C × 1.8 + 32; Fahrenheit to Celsius is (F − 32) × 5/9. Kelvin equals Celsius + 273.15. This gives 0°C = 32°F = 273.15 K, and 100°C = 212°F. Kelvin has no degree sign. The tool accepts negative Celsius and Fahrenheit readings down to absolute zero.
A practical example
0°C is 32°F and 273.15 K; 100°C is 212°F. These are temperature readings, so an offset is included as well as a scale factor.
A useful tip
Convert an actual thermometer reading here. A change of 10°C is a change of 18°F, but a reading of 10°C is 50°F. Those are different questions.
Good questions. Simple answers.
Why is a negative Kelvin value rejected?
Zero kelvin is absolute zero for the ordinary temperature scales used here. Values below 0 K, −273.15°C, or −459.67°F are rejected.
Does swapping change the temperature?
It moves the converted reading into the input and reverses the scales. The represented temperature stays the same, within numerical precision.
Explore all converters for related tasks and category-specific guidance, or read how Toolzafi handles your data.