Temperature Converter
Convert Celsius, Fahrenheit, Kelvin.
Convert Celsius, Fahrenheit, Kelvin.
This free Temperature Converter from KX Toolkit is part of our all-in-one online toolkit. It runs entirely in your browser, so your data never leaves your device for client-side operations. 100% free, forever - no paywall, no credit card, no trial.
How to use the Temperature Converter
- Pick the unit you have and the unit you want.
- Enter the value.
- Read the converted value - most tools update as you type.
- Use the swap button to reverse the direction if needed.
What you can do with the Temperature Converter
- Convert recipe ingredients between metric and imperial.
- Translate engineering specs across systems.
- Check shipping weights and dimensions before ordering.
- Quick travel conversions for distance, speed and currency.
Why use KX Toolkit's Temperature Converter
- Browser-based: Works on Windows, macOS, Linux, iOS and Android - no install, no extension.
- Privacy-first: Client-side tools never upload your data; server-side tools delete files right after processing.
- Mobile-friendly: Full feature parity on phones and tablets - not a stripped-down view.
- Fast: Optimised for instant feedback. No artificial waiting screens, no email-gated downloads.
- One hub for everything: 300+ tools across SEO, text, image, PDF, code, color, calculators and more - skip switching between sites.
Tips for the best results
For very large or very small numbers, use the scientific-notation option - it avoids floating-point rounding errors.
Related Unit Converter Tools
If you find this tool useful, explore the full Unit Converter Tools collection or browse our complete tool directory. KX Toolkit is built for marketers, developers, designers, students and anyone who needs a quick utility without signing up for yet another SaaS.
How do I convert Celsius to Fahrenheit?
Multiply the Celsius value by 9/5 and add 32. For example, 20 C times 1.8 equals 36, plus 32 equals 68 F. The reverse is Fahrenheit minus 32, then multiplied by 5/9. Body temperature 37 C becomes 98.6 F, and water boils at 100 C or 212 F. The converter applies the formula automatically and shows all three scales together.
What is the relationship between Celsius and Kelvin?
Kelvin and Celsius use the same step size, so a one-degree change is identical in both. The difference is the zero point: 0 K equals -273.15 C, which is absolute zero. To convert, add 273.15 to Celsius to get Kelvin, or subtract 273.15 from Kelvin to get Celsius. Kelvin is used in science because it has no negative values and starts at the lowest possible temperature.
Why does the United States still use Fahrenheit?
Fahrenheit was widely adopted in the US before metric standardisation, and weather forecasts, ovens, and HVAC systems all use it. Switching would require updating thermostats, recipes, and public familiarity, which has not happened. Most other countries use Celsius for daily life and Kelvin for science. The Bahamas, Cayman Islands, Liberia, and Palau also use Fahrenheit alongside the US.
At what temperature do Celsius and Fahrenheit match?
They are equal at -40 degrees: -40 C equals -40 F. This is a useful mnemonic for very cold weather and is the only point where the two scales cross. Above and below -40 they diverge, with Fahrenheit numbers higher than Celsius for any positive temperature you would normally encounter.
What is Rankine and when is it used?
Rankine is an absolute temperature scale like Kelvin but uses Fahrenheit-sized degrees. 0 R equals absolute zero, and 491.67 R equals the freezing point of water. It is mostly used in US engineering disciplines like thermodynamics and aerospace where Fahrenheit is the base unit but absolute values are needed. To convert Fahrenheit to Rankine, just add 459.67.
How accurate are the converted values?
The conversions are mathematically exact because the formulas are simple linear transforms. The displayed precision depends on rounding, usually two to four decimal places. For scientific work, copy the unrounded value if available. For everyday use like cooking or weather, one decimal is plenty since most thermometers are not more accurate than that anyway.
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