How to use the temperature converter
- Enter the temperature you want to convert in the value box.
- Choose the scale you are starting from and the scale you want to convert to.
- Press Convert. The result appears immediately.
- Read the formula line to see the exact relationship that produced the answer.
Why temperature is not a simple ratio
Most unit conversions are just multiplication by a constant — one meter is always 3.28084 feet. Temperature is different because the three scales do not share the same zero point. Zero degrees Celsius is 32 degrees Fahrenheit and about 273.15 kelvin, so converting between them requires both a scaling step and an offset. Multiplying a Celsius value by a fixed number would give the wrong answer every time.
This tool handles that correctly. It first converts your input to Celsius, applies the right offset, then converts from Celsius to the target scale using the proper formula.
The three temperature scales
Fahrenheit is the everyday scale in the United States, with water freezing at 32 °F and boiling at 212 °F. Celsius, used by most of the world, sets freezing at 0 °C and boiling at 100 °C. Kelvin is the scientific scale that starts at absolute zero — the coldest temperature that is physically possible — so it has no negative values. Because kelvin intervals are the same size as Celsius intervals, converting between those two is a simple addition or subtraction of 273.15. That shared interval size also means a change of one degree Celsius is exactly the same as a change of one kelvin, while one Celsius degree equals 1.8 Fahrenheit degrees.
The formulas
| Conversion | Formula |
|---|---|
| Celsius to Fahrenheit | F = C × 9/5 + 32 |
| Fahrenheit to Celsius | C = (F - 32) × 5/9 |
| Celsius to Kelvin | K = C + 273.15 |
| Kelvin to Celsius | C = K - 273.15 |
| Fahrenheit to Kelvin | K = (F - 32) × 5/9 + 273.15 |
| Kelvin to Fahrenheit | F = (K - 273.15) × 9/5 + 32 |