Temperature Converter
Convert temperatures instantly between Celsius, Fahrenheit, Kelvin, Rankine and Réaumur. Enter any temperature value, choose the source and destination units, and see all equivalent temperatures at once.
Convert Temperature
Enter a temperature and select the units you want to convert from and to.
All Temperature Conversions
The entered temperature converted into each supported scale.
Common Temperatures
Select a common Celsius value to convert instantly.
Celsius to Fahrenheit Conversion Table
Common temperature values converted between Celsius, Fahrenheit and Kelvin.
| Celsius | Fahrenheit | Kelvin | Common Reference |
|---|---|---|---|
| -40 °C | -40 °F | 233.15 K | Celsius and Fahrenheit are equal |
| -20 °C | -4 °F | 253.15 K | Very cold weather |
| 0 °C | 32 °F | 273.15 K | Freezing point of water |
| 10 °C | 50 °F | 283.15 K | Cool temperature |
| 20 °C | 68 °F | 293.15 K | Typical room temperature |
| 25 °C | 77 °F | 298.15 K | Warm room temperature |
| 30 °C | 86 °F | 303.15 K | Hot weather |
| 37 °C | 98.6 °F | 310.15 K | Common reference for body temperature |
| 40 °C | 104 °F | 313.15 K | Very hot weather |
| 100 °C | 212 °F | 373.15 K | Boiling point of water at standard pressure |
How to Use the Temperature Converter
Enter a temperature value, select the unit you are converting from and choose the unit you want to convert to. The result updates automatically as you type.
This temperature converter supports:
- Celsius to Fahrenheit;
- Fahrenheit to Celsius;
- Celsius to Kelvin;
- Kelvin to Celsius;
- Fahrenheit to Kelvin;
- Kelvin to Fahrenheit;
- Rankine conversions;
- Réaumur conversions; and
- Conversions between any two supported scales.
Celsius to Fahrenheit Formula
To convert Celsius to Fahrenheit:
For example, to convert 25°C to Fahrenheit:
(25 × 9 ÷ 5) + 32
= 45 + 32
= 77°F
Fahrenheit to Celsius Formula
To convert Fahrenheit to Celsius:
For example:
68°F = 20°C
Celsius to Kelvin Formula
Kelvin uses the same size temperature interval as Celsius, but starts from absolute zero.
For example:
25°C = 298.15 K
Kelvin to Celsius Formula
For example:
300 K = 26.85°C
Fahrenheit to Kelvin Formula
Kelvin to Fahrenheit Formula
What Is Celsius?
Celsius is a widely used temperature scale. Under common reference conditions, water freezes at approximately 0°C and boils at approximately 100°C at standard atmospheric pressure.
Celsius is commonly used in Australia and many other countries for weather, cooking, refrigeration, science and everyday temperature measurements.
What Is Fahrenheit?
Fahrenheit is another temperature scale commonly used in the United States and some other contexts.
On the Fahrenheit scale, water freezes at approximately 32°F and boils at approximately 212°F at standard atmospheric pressure.
What Is Kelvin?
Kelvin is an absolute thermodynamic temperature scale used extensively in science and engineering.
The Kelvin scale starts at absolute zero:
Kelvin values are normally written without a degree symbol. For example, the correct notation is 300 K, not 300°K.
What Is Absolute Zero?
Absolute zero is the lowest possible temperature on the thermodynamic temperature scale.
It corresponds to:
- 0 K;
- −273.15°C;
- −459.67°F; and
- 0°R.
The converter prevents Kelvin or Rankine values below absolute zero.
What Is Rankine?
Rankine is an absolute temperature scale that uses Fahrenheit-sized degrees.
Like Kelvin, Rankine begins at absolute zero.
What Is the Réaumur Scale?
Réaumur is a historical temperature scale in which the freezing point of water is 0°Ré and the boiling point is 80°Ré under traditional reference conditions.
It is much less commonly used today but is included for broader unit conversion.
Why Is −40 the Same in Celsius and Fahrenheit?
The Celsius and Fahrenheit scales intersect at −40.
This is the only temperature at which the numeric values on the Celsius and Fahrenheit scales are identical.
What Is 0°C in Fahrenheit?
0°C equals:
This is approximately the freezing point of water under standard reference conditions.
What Is 20°C in Fahrenheit?
20°C equals:
This is often used as a rough reference for comfortable room temperature.
What Is 25°C in Fahrenheit?
25°C equals:
What Is 30°C in Fahrenheit?
30°C equals:
What Is 100°C in Fahrenheit?
100°C equals:
This corresponds approximately to the boiling point of water at standard atmospheric pressure.
What Is 32°F in Celsius?
32°F equals:
What Is 68°F in Celsius?
68°F equals:
What Is 77°F in Celsius?
77°F equals:
What Is 100°F in Celsius?
Using the Fahrenheit-to-Celsius formula:
Temperature Conversion for Australia
Australia primarily uses Celsius for everyday temperature measurements, including weather forecasts, air conditioning, cooking and many household applications.
A temperature converter can be useful when reading information from countries or products that use Fahrenheit.
Temperature Converter Assumptions
This converter:
- Uses standard mathematical temperature conversion formulas;
- Supports positive and negative Celsius and Fahrenheit values;
- Prevents values below absolute zero;
- Displays Kelvin without a degree symbol;
- Rounds displayed results for readability;
- Uses standard reference values for common temperature examples; and
- Does not account for measurement-device accuracy or calibration.
Related Unit Converters
Temperature Converter FAQs
How do I convert Celsius to Fahrenheit?
Multiply the Celsius temperature by 9/5 and then add 32. For example, 25°C equals 77°F.
How do I convert Fahrenheit to Celsius?
Subtract 32 from the Fahrenheit value, then multiply the result by 5/9.
What is 0°C in Fahrenheit?
0°C equals 32°F.
What is 100°C in Fahrenheit?
100°C equals 212°F.
What is 25°C in Fahrenheit?
25°C equals 77°F.
What is absolute zero?
Absolute zero is 0 Kelvin, which equals −273.15°C and approximately −459.67°F.
Why does Kelvin not use a degree symbol?
Kelvin is an SI thermodynamic temperature unit and is written with the symbol K rather than °K.
At what temperature are Celsius and Fahrenheit equal?
Celsius and Fahrenheit have the same numeric value at −40: −40°C equals −40°F.