Kelvin to Celsius
Convert Kelvin to Celsius instantly. Free temperature converter, no signup.
How to use this tool
- Enter degrees kelvin in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your degrees celsius and the full breakdown beneath it.
Convert Kelvin to Celsius instantly. Free temperature converter, no signup.
Formula
Celsius = Kelvin − 273.15
°C = K − 273.15
Subtracting 273.15 reverses the Kelvin offset back to the Celsius scale, where water freezes at 0 °C.
How it works
Subtract 273.15 from the Kelvin value. Because the Kelvin and Celsius scales have identical degree sizes, the conversion is a simple fixed-constant shift. This is the inverse of the Celsius-to-Kelvin conversion and is commonly needed when working with scientific data expressed in Kelvin for everyday temperature interpretation.
Common mistake: A frequent error is adding 273.15 instead of subtracting it — this produces a Celsius value far too high and is the opposite of the correct operation.
Worked example
Convert 273.15 K (absolute freezing) to Celsius
- Start with 273.15 K (the input value).
- Apply the formula: °C = 273.15 − 273.15
- Result: 0 °C
0 °C — exactly the freezing point of water, confirming the conversion.
Common mistakes to avoid
- Subtracting 273 instead of 273.15, a 0.15 C error that propagates in thermodynamic equations.
- Confusing the formula with Fahrenheit conversion and applying a multiplier — Kelvin to Celsius requires only subtraction, no scaling.
- Entering a Kelvin value below 273.15 and not realizing the Celsius result will be negative (e.g., 200 K = -73.15 C).
Key terms
- Kelvin (K)
- The SI base unit for thermodynamic temperature, starting at absolute zero with no negative values.
- Celsius (°C)
- A temperature scale anchored to water's freezing point (0 °C) and boiling point (100 °C) at standard pressure.
- Absolute zero
- 0 K = −273.15 °C; the point at which particles theoretically cease all thermal motion.
- Thermodynamic temperature
- Temperature measured on an absolute scale starting at absolute zero, as opposed to an arbitrary reference like the freezing point of water.
Frequently asked questions
- What is 0 K in Celsius?
- 0 K - 273.15 = -273.15 C, known as absolute zero.
- What is room temperature in Kelvin?
- A typical room at 20 C equals 20 + 273.15 = 293.15 K.
- Do I need to scale the value, or just subtract?
- Just subtract 273.15. The Kelvin and Celsius scales have identical degree sizes; they differ only by their zero point.