The Celsius scale sets water’s freezing point at 0 °C and boiling point at 100 °C at sea level. It is used for weather, cooking and medicine almost everywhere outside the U.S.
How to use the Celsius Converter
- Pick the unit you are starting from in the From menu and type your value.
- Pick the unit you want in the To menu. The heading changes to match – for example “Degrees Celsius to Degrees Fahrenheit Converter”.
- The most common temperature units are shown below at the same time, so you can compare them at a glance.
- Type into any result to convert backwards, then use Copy results – the copied text starts with the heading for your chosen units.
Results update as you type. Everything is calculated in your browser.
How it works
Every temperature unit is defined by an exact factor relative to the degree Celsius (the base unit). The calculator first turns the value you type into degrees Celsius, then turns that into the unit you picked in the “To” menu and into each of the common units below it. This two-step method means any unit can be converted to any other – 8 units are available in each menu – and you can type into any field, including a result, to work in the other direction. Changing a unit menu keeps the quantity the same and just re-expresses it, and the page heading and copied results follow your choice.
How to convert temperature units
- Choose the unit you have in the From menu and type the value.
- Choose the unit you want in the To menu – the heading changes to match, for example “Degrees Celsius to Degrees Fahrenheit Converter”.
- The calculator converts through the base scale using each unit’s scale factor and zero offset.
1 degree Celsius in common units
| Unit | Value |
|---|---|
| Degrees Fahrenheit (°F) | 33.8 |
| Kelvins (K) | 274.15 |
| Degrees Rankine (°R) | 493.47 |
| Degrees Réaumur (°Ré) | 0.8 |
Degrees Celsius conversion table
| Degrees Celsius | °F | K | °R | °Ré |
|---|---|---|---|---|
| -40 | -40 | 233.15 | 419.67 | -32 |
| -10 | 14 | 263.15 | 473.67 | -8 |
| 0 | 32 | 273.15 | 491.67 | 0 |
| 10 | 50 | 283.15 | 509.67 | 8 |
| 20 | 68 | 293.15 | 527.67 | 16 |
| 25 | 77 | 298.15 | 536.67 | 20 |
| 30 | 86 | 303.15 | 545.67 | 24 |
| 37 | 98.6 | 310.15 | 558.27 | 29.6 |
| 100 | 212 | 373.15 | 671.67 | 80 |
| 180 | 356 | 453.15 | 815.67 | 144 |
What is a degree Celsius?
The Celsius scale sets 0 °C at the freezing point and 100 °C at the boiling point of water at sea level. Since 2019 it is defined from the kelvin: °C = K − 273.15.
What is a degree Fahrenheit?
The Fahrenheit scale, proposed by Daniel Fahrenheit in 1724, puts water’s freezing point at 32 °F and boiling point at 212 °F. It is the everyday scale in the United States.
What is a kelvin?
The kelvin is the SI unit of temperature. It starts at absolute zero, the coldest possible temperature, and has the same step size as the degree Celsius.
Common mistakes to avoid
Forgetting the offset (°f is not just °c × 1.8), converting temperature differences with the full formula (a change of 10 °c is a change of 18 °f, with no +32), and writing “degrees kelvin”.
Formula
°F = °C × 9/5 + 32K = °C + 273.15°R = (°C + 273.15) × 9/5Worked example
Inputs — From: 20 °C.
Results — To = 68 °F; Kelvins = 293.15 K; Degrees Rankine = 527.67 °R; Degrees Réaumur = 16 °Ré.
Frequently asked questions
What is 20 °C in Fahrenheit?
68 °F.
What is 0 °C in kelvin?
273.15 K.
Is centigrade the same as Celsius?
Yes; “centigrade” was the older name, officially replaced in 1948.
How do I change the units?
Pick any unit in the From and To menus. The value is converted in place, and the heading changes to show your conversion, for example “Degrees Celsius to Degrees Fahrenheit Converter”.
Can I type into any field?
Yes. Every field is editable, so you can start from whichever unit you have.
How many units can I convert between?
8 temperature units, from the everyday to the specialised.
Which units are exact?
All factors here are exact by definition except astronomical and similar reference values, which use internationally agreed constants.
What formula does the Celsius Converter use?
°F = °C × 9/5 + 32.