Convert temperatures instantly. This free temperature converter switches between Celsius, Fahrenheit and Kelvin from any starting unit, with conversion formulas and a reference table of common temperatures.
Convert from
°C
Enter a temperature and pick its unit. The other two scales update instantly. Kelvin is an absolute scale, so it can’t go below 0 K (−273.15 °C).
Fahrenheit
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Enter a temperature
Celsius
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Fahrenheit
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Kelvin
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Reference
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Celsius and Fahrenheit meet at −40° (−40 °C = −40 °F). Water freezes at 0 °C / 32 °F / 273.15 K and boils at 100 °C / 212 °F / 373.15 K at sea level.
Use this free temperature converter to convert between Celsius, Fahrenheit and Kelvin. Enter a temperature in any scale and see the other two update instantly.
What this temperature converter does
A temperature converter changes a temperature between Celsius (°C), Fahrenheit (°F) and Kelvin (K). Pick the unit you’re starting from, enter the value, and all three scales are shown together.
Temperature conversion formulas
°F = °C × 9/5 + 32
°C = (°F − 32) × 5/9
K = °C + 273.15
So 25 °C = 77 °F = 298.15 K, and normal body temperature 37 °C = 98.6 °F.
Common temperatures
Reference
°C
°F
K
Absolute zero
−273.15
−459.67
0
Water freezes
0
32
273.15
Body temperature
37
98.6
310.15
Water boils
100
212
373.15
Why Celsius and Fahrenheit meet at −40
The two scales cross at −40°: −40 °C equals −40 °F. It’s the one point where the formulas give the same number, a handy fact to remember.
How to use the temperature converter
Pick the starting unit (°C, °F or K).
Enter the temperature.
Read all three scales instantly.
Temperature Converter FAQ
How do I convert Celsius to Fahrenheit?
Multiply by 9/5 and add 32. So 25 °C × 9/5 + 32 = 77 °F. The converter does it instantly in either direction.
How do I convert Fahrenheit to Celsius?
Subtract 32, then multiply by 5/9. For example, (98.6 − 32) × 5/9 = 37 °C.
How do I convert Celsius to Kelvin?
Add 273.15. So 0 °C is 273.15 K and 100 °C is 373.15 K. Kelvin can't go below 0.
What is normal body temperature?
About 37 °C, which is 98.6 °F or 310.15 K, though normal varies slightly from person to person.
At what temperature are Celsius and Fahrenheit equal?
At −40°: −40 °C equals −40 °F. It's the single point where the two scales meet.
Is the temperature converter free?
Yes, this temperature converter is completely free, needs no sign-up, and gives instant results in your browser.
