Temperature Converter
Convert between Celsius, Fahrenheit and Kelvin.
Your figures
Result
How to use this tool
- Enter your own figures over the defaults — Value, From.
- The answer updates as you type. There is no button, and nothing is sent anywhere.
- Change one input at a time to see how sensitive the answer is to it.
Celsius and Fahrenheit meet at −40 degrees, the only point where both scales read the same.
How it works
This takes 2 inputs — value, from — and returns celsius, fahrenheit and kelvin. The whole calculation happens in this page as you type: there is no submit button, no request, and nothing stored.
A worked example
Worked through with the figures the page already has in it: value of 25 and from of Celsius, giving celsius of 25.00 °C. These numbers come from running the calculator’s own code, not from being typed in here, so they cannot drift away from what you see on screen.
Starting from:
- Value: 25
- From: Celsius
| Result | Value |
|---|---|
| Celsius | 25.00 °C |
| Fahrenheit | 77.00 °F |
| Kelvin | 298.15 K |
Temperature Converter — frequently asked questions
How do I convert C to F?
Multiply by 9/5 and add 32. For a rough mental estimate, double it and add 30.
What is absolute zero?
−273.15 °C, or 0 K — the point at which molecular motion is at its minimum.
Why does Kelvin have no degree symbol?
Kelvin is an absolute scale, so its units are simply kelvins rather than degrees.
Is this calculator free?
Yes, with no account, no limits and no data collection. It runs entirely in your browser.
Should I rely on this for a financial or medical decision?
No. It is a planning estimate built on standard formulas and stated assumptions. For decisions that matter, speak to a qualified professional who can account for your full circumstances.
Is this calculator accurate?
The arithmetic is exact — it uses the standard formula. What limits accuracy is the assumptions: the figures you enter, and factors the formula does not model such as fees, taxes and rule changes.
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Nothing is sent anywhere. The figures you type stay in this page and are never transmitted or stored — how that works.
Disclaimer. The formula is exact; the answer is only as good as the figures and assumptions above. Not financial, tax, medical or legal advice. Full disclaimer.