Convert between Fahrenheit and Celcius
Conversion Formulas between °F and °C :
°C = (°F - 32) × 5/9
°F = °C × 9/5 + 32
Fahrenheit Scale was defined by the German physicist Daniel Gabriel Fahrenheit (1686–1736). The zero point is determined by the temperature of a mixture of ice, water, and ammonium chloride at a 1:1:1 ratio that has a stable temperature of 0 °F (−17.78 °C). Intervals between this point and the freezing point of water and normal body temperature were chosen to be easily divisible without leaving fractions.
Celcius scale was defined by Swedish astronomer Anders Celsius (1701–1744).
Current scientific definition uses absolute zero (-273.15°C) and the triple point of water as fixed points. The triple point of water is where ice, liquid water and water vapour coexist in thermal equilibrium and occurs at 0.01°C.
Absolute zero (-273.15) is the lowest temperature possible. Entropy reaches its minimum value, classical kinetic energy and so thermal energy is zero. This is taken as zero point of Kelvin scale of temperature which has the same interval as Celcius scale (i.e. Δ1°C = Δ1K).