Celsius to Kelvin
Why Kelvin matters
Kelvin is the SI absolute scale: 0 K is absolute zero, and one kelvin step equals one Celsius degree step. Convert Celsius by adding 273.15 (not 273 for precise lab work). Relative deltas—"rise 10 °C" versus "rise 10 K"—are identical in size.
When to use it
Physics homework, semiconductor junction specs quoted in °C that you must feed into formulas expecting K, or comparing cryogenic limits where negative Celsius values become small positive kelvins. For weather-only talk you rarely need K—use Celsius to Fahrenheit instead.