Temperature Converter
- (100 + 459.67) / 1.8 310.9277778 kelvin
- 310.9277778 - 273.15 37.8 degree Celsius
This page converts a temperature from one unit into another. Every value passes through the kelvin, the SI unit temperature is held in, and temperature stays temperature: a unit only converts inside its own dimension.
How do you convert a temperature between Celsius, Fahrenheit and Kelvin?
Pick the unit you have, pick the unit you want, and type the value. The page applies the formula between the two scales and prints the arithmetic under the result, so the answer and the working are the same object.
20 degC is 68 degF and 293.15 K. Multiply Celsius by 1.8 and add 32 for Fahrenheit; add 273.15 to Celsius for kelvin.
- Choose the unit your value is in. This page opens on the degree Fahrenheit.
- Choose the unit you want it in. This page opens on the degree Celsius.
- Type the value. The result and the factor behind it appear together.
- Read the working. It converts into the kelvin first and out again, which is the same two lines you would write by hand.
Temperature Conversion Table
Each scale has a starting point as well as a step size, so every pair below is a formula rather than a factor. The wording is the knowledge base's own.
| From | To | Formula |
|---|---|---|
| kelvin | degree Celsius | t/degC = T/K - 273.15 |
| kelvin | degree Fahrenheit | t/degF = T/K x 1.8 - 459.67 |
| kelvin | degree Rankine | T/degR = T/K x 1.8 |
| degree Celsius | kelvin | T/K = t/degC + 273.15 |
| degree Celsius | degree Fahrenheit | t/degF = t/degC x 1.8 + 32 |
| degree Celsius | degree Rankine | T/degR = t/degC x 1.8 + 491.67 |
| degree Fahrenheit | kelvin | T/K = (t/degF + 459.67) / 1.8 |
| degree Fahrenheit | degree Celsius | t/degC = (t/degF - 32) / 1.8 |
| degree Fahrenheit | degree Rankine | T/degR = t/degF + 459.67 |
| degree Rankine | kelvin | T/K = (T/degR) / 1.8 |
| degree Rankine | degree Celsius | t/degC = (T/degR - 491.67) / 1.8 |
| degree Rankine | degree Fahrenheit | t/degF = T/degR - 459.67 |
Worked Examples
The questions the bank ranked highest for this page, answered with the working.
What is 100 degF in Celsius?
- (100 + 459.67) / 1.8 310.9277778 kelvin
- 310.9277778 - 273.15 37.8 degree Celsius
100 degF = 37.8 degC
What is 37 degC in Fahrenheit?
- 37 + 273.15 310.15 kelvin
- 310.15 x 1.8 - 459.67 98.6 degree Fahrenheit
37 degC = 98.6 degF
Where These Factors Come From
Every number above is read from the knowledge base rather than computed for the page. These are the statements it holds for temperature.
- Kelvin and Celsius use the same size of degree and differ only by an offset: T/K = t/degC + 273.15. Absolute zero is 0 K, which is -273.15 degC.
- Celsius and Fahrenheit differ in both step size and starting point: t/degC = (t/degF - 32) / 1.8, and t/degF = t/degC x 1.8 + 32. The two scales read the same at -40.
- absolute zero, value in celsius -273.15
- absolute zero, value in fahrenheit -459.67
- Celsius and Fahrenheit, equal reading -40
- Most units convert by a ratio alone, so zero maps to zero. Celsius and Fahrenheit do not: their scales start at different points, so each conversion needs an offset as well as a ratio.
- How this page reports a result result on the target scale, offset applied before rounding, one decimal place by default
Why Does Temperature Need an Offset?
Most units convert by a ratio alone, so zero maps to zero. The Celsius and Fahrenheit scales start in different places, so each conversion needs a starting point as well as a step size, and the offset is applied before the result is rounded.
The rule behind this factor is the same for every unit - why temperature needs an offset.
Frequently Asked Questions
Why does temperature use an offset and not just a factor?
Because the scales do not start in the same place. A ratio on its own maps zero to zero, and zero on one scale is not zero on the other, so every conversion needs a starting point as well as a step size.
At what temperature do Celsius and Fahrenheit read the same?
-40. Both scales give -40 there.
Is it kelvin or degrees kelvin?
Kelvin, with no degree sign: 293.15 K, not 293.15 degK.
How do you convert Fahrenheit to Kelvin?
T/K = (t/degF + 459.67) / 1.8.
Related Conversions
The rest of the family sits on the unit converter index.