Temperature Converter

Convert temperatures between Celsius, Fahrenheit, Kelvin and Rankine. Type a temperature, choose its unit and see all four results at once.

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Results are rounded to 2 decimal places. Absolute zero is -273.15 C, -459.67 F, 0 K and 0 R.

How to Use the Temperature Converter

  1. Type the temperature in the box.
  2. Choose the unit you are converting from: Celsius, Fahrenheit, Kelvin or Rankine.
  3. Read the result in all four units. The unit you chose is highlighted.

Temperature Formulas

  • Celsius to Fahrenheit: F = C times 9/5 plus 32.
  • Fahrenheit to Celsius: C = (F minus 32) times 5/9.
  • Celsius to Kelvin: K = C plus 273.15.
  • Kelvin to Celsius: C = K minus 273.15.
  • Fahrenheit to Rankine: R = F plus 459.67.

Handy Temperatures

  • Water freezes at 0 C, 32 F, 273.15 K.
  • Water boils at 100 C, 212 F, 373.15 K at sea level.
  • Normal body temperature is about 37 C or 98.6 F.
  • A comfortable room is around 20 to 22 C, or 68 to 72 F.
  • Absolute zero, the coldest possible temperature, is -273.15 C, -459.67 F or 0 K.

Good to Know

  • Celsius is used in most countries. Fahrenheit is used mainly in the United States.
  • Kelvin is the scientific unit. It starts at absolute zero and has no negative values.
  • Rankine is like Kelvin but uses Fahrenheit-sized degrees. It is used in some engineering work.
  • The tool rejects temperatures below absolute zero, because they cannot exist.

Frequently Asked Questions

Is this temperature converter free?

Yes. It is free to use, with no sign-up. Everything is worked out in your browser.

How do I convert Celsius to Fahrenheit?

Multiply by 9, divide by 5 and add 32. For example, 20 C is 20 times 9 divided by 5 plus 32, which is 68 F.

What is 0 Kelvin in Celsius?

0 K is -273.15 C. It is called absolute zero.

Why is there no degree sign for Kelvin?

By convention Kelvin is written as K, not degrees K, because it is an absolute scale.

Can I convert other units?

Yes. Use the Unit Converter for length, weight, volume, area, speed, time, storage and energy.

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