373 K=99.85°C

To convert 373 K to Celsius, subtract 273.15: 373 − 273.15 = 99.85°C. The constant 273.15 is the magnitude of absolute zero expressed in Celsius (−273.15°C), and subtracting it shifts the Kelvin value onto the Celsius scale. Because one Kelvin degree and one Celsius degree are the same size, no scaling is needed — the conversion is a simple offset.

The Kelvin scale begins at absolute zero, the lowest theoretically possible temperature, where particles have minimum thermal energy. Unlike Celsius and Fahrenheit, Kelvin has no negative values, which makes it the standard in scientific disciplines that require precise thermodynamic calculations. Fields such as astrophysics, quantum mechanics, cryogenics, and physical chemistry routinely express temperatures in Kelvin. Converting those Kelvin readings to Celsius provides an intuitive sense of scale — most people have a feel for what −20°C or 150°C means in everyday terms, even if Kelvin values are harder to interpret at a glance.

In practice, 373 K equals 99.85°C, a value that may appear in laboratory reports, scientific literature, or engineering data sheets. Understanding this conversion is important for researchers who need to explain results to non-specialist audiences, for engineers calibrating instruments, and for students moving between scientific notation and everyday reference. Notable Kelvin benchmarks include 0 K (absolute zero, −273.15°C), 273.15 K (0°C, freezing water), 373.15 K (100°C, boiling water), and 310.15 K (37°C, human body temperature).