Temperature Converter

This free online temperature conversion tool makes it easy to convert a temperature value between the most commonly used temperature scales. Whether you’re working with weather data, scientific measurements, cooking temperatures, or engineering calculations, this calculator provides fast and accurate conversions.

With this temperature calculator, you can convert between Celsius, Kelvin, and Fahrenheit instantly. Simply enter a value into any of the available input fields, and the calculator will automatically calculate and display the equivalent temperatures across all other supported scales. This real-time conversion eliminates the need for manual formulas and ensures consistent, reliable results.

Enter temperature

Celsius

°C

Fahrenheit

°F

Kelvin

K

Rankine

°R

Decimal places

Calculated in your browser as you type. Negative values are fine, but nothing can be colder than 0 K (absolute zero).

How to use it

The temperature conversion calculator is a handy webtool to use to convert from one temperature to another.

Enter a valueType a temperature into any one of the fields. Negative numbers and the ‘e’ exponent such as 1e3 are accepted.
Read the resultsAll the other fields update automatically with the converted temperatures.
Copy a valueClick the clipboard button beside any field to copy it.
Tidy the numbersUse Decimal places to round the results, or leave it on full precision.

Handy conversions

Water freezes

At 0 °C, 32 °F and 273.15 K.

Water boils

At 100 °C, 212 °F and 373.15 K at sea level.

Same in both

-40 °C is exactly -40 °F, the one point where the two scales meet.

Temperature unit comparison table

Unit name	Symbol	Description	Reference point
Celsius	°C	Common temperature scale for weather and daily use	0°C = water freezes
Fahrenheit	°F	Primarily used in the United States	32°F = water freezes
Kelvin	K	SI base unit of temperature used in science	0 K = absolute zero
Rankine	°R	Absolute scale using Fahrenheit-sized degrees, used in some engineering	0 °R = absolute zero

Key notes

Everyday use

Celsius is widely used worldwide for everyday temperature measurements.

Absolute scales

Kelvin does not use degrees and is based on absolute zero. Rankine is the Fahrenheit-sized equivalent.

Different step sizes

A Fahrenheit degree is smaller than a Celsius degree: 1 °C is 1.8 °F.

Negative values

Negative values are possible in Celsius and Fahrenheit, but not in Kelvin or Rankine.

Frequently asked questions

How do I convert Celsius to Fahrenheit?

Multiply by 1.8 and add 32. For example 20 °C × 1.8 + 32 = 68 °F.

How do I convert Fahrenheit to Celsius?

Subtract 32, then divide by 1.8. For example (98.6 − 32) ÷ 1.8 = 37 °C.

How do I convert Celsius to Kelvin?

Add 273.15. A Kelvin degree is the same size as a Celsius degree, so only the starting point differs.

What is absolute zero?

It is the lowest possible temperature: 0 K, -273.15 °C, -459.67 °F or 0 °R. If you enter a value below it, the tool still calculates, but no real object can reach it.

What is Rankine used for?

It is an absolute scale with Fahrenheit-sized degrees, used in some US thermodynamics and engineering work.

Is anything sent to a server?

No. The conversion is calculated in your browser as you type.