Free Temperature Converter – Celsius, Fahrenheit & Kelvin
Convert between Celsius, Fahrenheit and Kelvin.
About the Temperature Converter
What is the Temperature Converter?
A temperature converter changes a temperature between Celsius, Fahrenheit and Kelvin.
Why use this calculator?
Weather, cooking and science each favour a different scale, and because temperature uses offsets rather than a simple ratio, hand conversion is error prone.
How to use it
- Enter the temperature value.
- Choose the scale you have and the scale you want.
- Read the result, plus all three scales for reference.
Formula
°F = °C × 9/5 + 32; K = °C + 273.15.
Kelvin has no degree symbol and starts at absolute zero; negative Kelvin values are impossible in nature.
Frequently Asked Questions
At what temperature are Celsius and Fahrenheit equal?
At −40 degrees: −40 °C equals −40 °F.
What is absolute zero?
It is 0 K, equal to −273.15 °C or −459.67 °F, the coldest temperature physically possible.
How precise are the conversions?
Conversions use standard, internationally defined factors and are rounded for display. They are accurate to the number of digits shown.
Can I convert back and forth without losing accuracy?
Yes. Enter the original value to get an exact inverse conversion; avoid chaining rounded results if you need maximum precision.
Which measurement system is used?
Both metric (SI) and US customary / imperial units are supported and clearly labelled.
Is this calculator free to use?
Yes. Every calculator on this site is completely free, with no hidden fees, no subscriptions and no limits on how many times you can use it.
How accurate are the results?
We use standard, widely accepted formulas and calculate in your browser using double-precision arithmetic. Results are rounded for readability, so treat them as reliable estimates rather than a guarantee. Real-world factors can vary the true figure.
Can I add this calculator to my own website?
Yes. Open this calculator page and use the "Add to your website" box in the sidebar to copy a ready-made iframe snippet, then paste it into any HTML page.
Does it work on a phone or tablet?
Yes. The layout is fully responsive, so it works on desktops, laptops, tablets and mobile phones, and every input adapts to touch screens.
Is the information I type kept private?
Yes. All calculations run locally in your browser. Nothing you enter is uploaded, stored or shared with anyone.