Temperature Converter

Enter one reading and see all three scales

Type a temperature, choose its unit, and select Convert temperature. The tool reports equivalent Celsius, Fahrenheit, and Kelvin values rounded to a useful display precision.

Three scales, different zero points

Celsius and Fahrenheit use degrees and choose different zero points and interval sizes. Kelvin uses the same interval size as Celsius but begins at absolute zero. Kelvin values are written without a degree symbol. A temperature change of 1 kelvin equals a change of 1 degree Celsius, even though their displayed values differ by 273.15.

Conversion formulas

Convert Celsius to Fahrenheit with F = C × 9/5 + 32. Convert Fahrenheit to Celsius with C = (F − 32) × 5/9. Kelvin equals Celsius + 273.15. The tool first converts the input to Celsius, then derives the other two readings, which keeps all paths consistent.

Worked example

Enter 20 Celsius. Multiplying by 9/5 gives 36, then adding 32 gives 68 Fahrenheit. Adding 273.15 gives 293.15 kelvin. For another familiar reference, water freezes at 0 Celsius, 32 Fahrenheit, or 273.15 kelvin under the usual standard-pressure reference conditions.

Temperature versus temperature difference

Converting a reading is not the same as converting an interval. A 10-degree Celsius increase equals an 18-degree Fahrenheit increase, but a reading of 10 Celsius equals 50 Fahrenheit because the zero-point offset also applies. Kelvin and Celsius differences have the same numeric size. Keep this distinction in mind for specifications that describe tolerances rather than measured readings.

Limits and assumptions

Values below absolute zero are rejected: below −273.15 Celsius, −459.67 Fahrenheit, or 0 kelvin. Display rounding does not increase instrument accuracy. Actual freezing and boiling points vary with pressure and substance purity. This converter does not interpret weather “feels like” values, oven calibration, significant figures, scientific uncertainty, or sensor error.