Temperature Conversion Is Not Just F to C (The Edge Cases Will Surprise You)

Fahrenheit to Celsius. Everyone knows the formula: C = (F - 32) * 5/9. But in practice, temperature conversion has nuances that trip up developers, scientists, and engineers regularly. The four scales and when each matters Fahrenheit (F): Used in the US for weather, cooking, and everyday life. Water freezes at 32F, boils at 212F. The scale was originally calibrated to 0F as the temperature of a brine solution and 96F as human body temperature (later revised to 98.6F). Celsius (C): Used everywhere else for everyday life and in all scientific contexts. Water freezes at 0C, boils at 100C. Clean, intuitive scale anchored to water's phase transitions. Kelvin (K): The SI unit of temperature. Identical scale to Celsius but shifted so that 0K is absolute zero (-273.15C). Used in physics, chemistry, and engineering. Kelvin has no degree symbol -- it is "300 K," not "300 degrees K." Rankine (R): The Fahrenheit equivalent of Kelvin. 0R is absolute zero. Used in some US engineering contexts, parti