UtilTools

Temperature Converter

Celsius, Fahrenheit, Kelvin and Rankine at once.

Temperature Converter turns any temperature into Celsius, Fahrenheit, Kelvin and Rankine simultaneously, and shows the formula behind each conversion. It also flags physical reference points — absolute zero, freezing, body temperature, boiling — so an obviously wrong entry is easy to spot. The arithmetic runs in your browser.

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Runs entirely on your device. No file or text you enter here is uploaded. How to verify it.

How to use Temperature Converter

  1. Type a temperature in any scale.
  2. Read the equivalents in the other three.
  3. Check the reference points if the result looks surprising.

Questions about Temperature Converter

What is the formula?
Celsius to Fahrenheit is °C × 9/5 + 32; the reverse is (°F − 32) × 5/9. Kelvin is Celsius plus 273.15. The offset is the part people drop, which is why "double it and add 30" gets you roughly there and never exactly.
Is there a temperature where C and F meet?
Yes, −40. It is the only point where the two scales give the same number, which makes it a handy sanity check for any converter.
Why does Kelvin have no degree sign?
Because it is an absolute thermodynamic scale, not a relative one — the SI convention is "295 K", never "295 °K". Absolute zero is 0 K, −273.15 °C, and the tool refuses to go below it.
Who still uses the Rankine scale?
Some US engineering work, particularly thermodynamics and combustion, where an absolute scale with Fahrenheit-sized degrees is convenient. Rankine is to Fahrenheit what Kelvin is to Celsius: 0 °R is absolute zero, and water freezes at 491.67 °R.
Can I use this for an oven or a fever reading?
Yes, and the reference points make it obvious when something is off — body temperature and the boiling point of water are both marked. For oven work with gas marks and fan-oven adjustments, the cooking converter covers that specifically.
Is Temperature Converter really free, with no limits?
Yes. There is no account, no daily cap, no file-size tier and no watermark, because there is no server cost to recover. The site is funded by clearly disclosed partner recommendations on the Partners page, never by metering the tools.
Are my files or text uploaded when I use Temperature Converter?
No. Everything is processed by JavaScript running in your browser, on your device. You can verify it: open your browser's developer tools, switch to the Network tab, and use the tool. You will see no request carrying your data — because there is nowhere for it to go.