Units

Temperature Converter

Convert Celsius, Fahrenheit, Kelvin and Rankine in real time. Enter a value, choose units and see the result with clear formulas.

Quick answer

The temperature converter transforms values between Celsius, Fahrenheit, Kelvin and Rankine. It calculates the target unit automatically and shows equivalent values in the main scales.

How to use the temperature converter

  1. Enter the temperature value.
  2. Select the source unit and target unit.
  3. The result updates automatically; use swap to invert the conversion.
  4. Copy the converted value when you need to reuse it.

Accepted formats

The converter accepts positive and negative decimal numbers for Celsius and Fahrenheit. Kelvin and Rankine must be zero or above because they start at absolute zero.

Conversion formulas

F = C x 9/5 + 32
C = (F - 32) x 5/9
K = C + 273.15

Practical example

25 C is equal to 77 F, 298.15 K and 536.67 R. This is a common room-temperature example.

How to interpret the result

Celsius and Fahrenheit are common in daily use. Kelvin is common in science and engineering because it starts at absolute zero.

Useful tips

  • Use Celsius for most international contexts.
  • Use Fahrenheit when preparing values for audiences in the United States.
  • Use Kelvin in scientific calculations where absolute temperature matters.

Frequently asked questions

How do I convert Celsius to Fahrenheit?

Multiply the Celsius value by 9/5 and add 32. For example, 25 C equals 77 F.

Can Kelvin be negative?

No. Kelvin starts at absolute zero, so values below 0 K are not physically valid.

What is the difference between Celsius and Kelvin?

Both use the same interval size, but Kelvin starts at absolute zero. K = C + 273.15.