ToolFoxTemperature Converter
Convert between Celsius, Fahrenheit and Kelvin — edit any of the three linked fields.
Edit any field — the other two update instantly.
How it works
Unlike length or weight, temperature scales are not simple multiples of each other because Fahrenheit and Celsius have different zero points. Every conversion routes through Celsius: Fahrenheit converts to Celsius as (F − 32) × 5⁄9, and Celsius converts to Kelvin by adding 273.15. Editing any one of the three fields recalculates the other two instantly.
Example
Water boils at 100°C, 212°F and 373.15K, and freezes at 0°C, 32°F and 273.15K. At −40 degrees, Celsius and Fahrenheit happen to read the same number — the only point where the two scales cross.
Frequently asked questions
Why can't temperature use the same factor-based converter as length or weight?
Because Celsius and Fahrenheit have different zero points (0°C is 32°F, not 0°F), so a simple multiplication factor cannot convert between them — an offset is required, which is why temperature gets its own formula.
Is Kelvin ever negative?
No — Kelvin is an absolute scale starting at absolute zero (−273.15°C), so 0K is the coldest possible temperature and the value can never go below zero.
What is the −40 crossover about?
−40°C and −40°F are numerically identical — solving the conversion formula for equality gives exactly −40, the one temperature where both scales agree.
Does editing Kelvin update Celsius and Fahrenheit too?
Yes — all three fields stay in sync; whichever one you type into becomes the source, and the other two are recalculated from it.
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