Temperature Converter

Convert temperatures between Celsius, Fahrenheit, Kelvin, Rankine and Réaumur. Type a value and the converted temperature appears straight away.

How to use the Temperature Converter

  1. Type the value you want to convert in the first box.
  2. Choose the unit you are converting from and the unit you want to convert to.
  3. Read the result instantly. Use the swap button to reverse the direction, or copy the result with one click.

Popular temperature conversions

ConversionResultFormula
Celsius to Fahrenheit1 °C = 33.8 °FFahrenheit = Celsius × 1.8 + 32
Fahrenheit to Celsius1 °F = -17.2222 °CCelsius = (Fahrenheit − 32) ÷ 1.8
Celsius to kelvin1 °C = 274.15 Kkelvin = Celsius + 273.15
Kelvin to Celsius1 K = -272.15 °CCelsius = kelvin − 273.15
Fahrenheit to kelvin1 °F = 255.928 Kkelvin = (Fahrenheit + 459.67) ÷ 1.8
Kelvin to Fahrenheit1 K = -457.87 °FFahrenheit = kelvin × 1.8 − 459.67

Supported temperature units

UnitSymbolEqual to
Degree Celsius°Csee formula
Degree Fahrenheit°Fsee formula
KelvinK1 K
Degree Rankine°R0.55555556 K
Degree Réaumur°Résee formula

Temperature conversion formulas

  • Celsius to Fahrenheit: °F = °C × 9/5 + 32
  • Fahrenheit to Celsius: °C = (°F − 32) × 5/9
  • Celsius to Kelvin: K = °C + 273.15
  • Fahrenheit to Kelvin: K = (°F + 459.67) × 5/9

Unlike most units, temperature scales do not share a zero point, so converting needs both a multiplication and an addition. Celsius and Fahrenheit meet at −40°, where −40 °C equals −40 °F.

Reference points

Point °C °F K
Absolute zero −273.15 −459.67 0
Water freezes 0 32 273.15
Room temperature 20 68 293.15
Body temperature 37 98.6 310.15
Water boils (sea level) 100 212 373.15

Frequently asked questions

How do I convert Celsius to Fahrenheit?

Multiply the Celsius temperature by 1.8 (9/5) and add 32. For example, 25 °C × 1.8 + 32 = 77 °F.

How do I convert Fahrenheit to Celsius?

Subtract 32 from the Fahrenheit temperature and multiply by 5/9. For example, (98.6 − 32) × 5/9 = 37 °C.

At what temperature are Celsius and Fahrenheit equal?

At −40 degrees. −40 °C and −40 °F are the same temperature.

What is absolute zero?

Absolute zero is 0 K, which equals −273.15 °C or −459.67 °F. It is the lowest possible temperature.

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