Celsius to Kelvin Converter

How to convert Celsius to Kelvin?

To convert Celsius to Kelvin, you can use the following formula: **K = °C + 273.15**. Simply add 273.15 to the Celsius temperature.

T_(K) = T_(°C) + 273.15

Example

Convert 20°C to Kelvin:

T_(K) = 20°C + 273.15 = 293.15K

What is the formula to convert Celsius to Kelvin?

Add 273.15 to the Celsius value: K = °C + 273.15. The offset 273.15 is exact by SI definition since the 2019 redefinition that fixed the Boltzmann constant.

Why does the formula use 273.15 instead of 273?

273.15 K is the freezing point of water at 1 atm. Using 273 introduces an 0.15 K error, which matters in cryogenics, semiconductor processing and scientific work. Always use 273.15.

What is absolute zero in Celsius?

Absolute zero is 0 K = −273.15 °C. At this temperature all classical molecular motion stops; reaching it exactly is forbidden by the third law of thermodynamics.

Do I write Kelvin with a degree symbol?

No. Kelvin is an absolute scale, so you write 300 K, never 300 °K. The degree symbol was officially dropped in 1967 by the 13th CGPM. Celsius keeps °C because it is a relative scale.

How is the Kelvin defined today?

Since 20 May 2019, the kelvin is defined by fixing the Boltzmann constant k_B at 1.380649×10⁻²³ J/K. Before that it was defined via the triple point of water (273.16 K).

What temperature is the human body in Kelvin?

Normal body temperature 37 °C = 310.15 K. A fever of 39 °C is 312.15 K. Room temperature 20–25 °C is 293–298 K, often rounded to 293 K in physics.

Where is the Kelvin scale used in daily life?

Color temperature of light bulbs (2700 K warm white, 6500 K daylight), CPU and GPU temperature sensors in some BIOS readouts, astronomy (star surface temperature), and HVAC engineering calculations.

Can Kelvin be negative?

Not on the conventional scale — 0 K is the lower bound. 'Negative absolute temperatures' exist in specially prepared quantum systems with bounded energy, but they are hotter than any positive temperature, not colder.

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