Work out temperature converter instantly with clear inputs, formula shown and shareable results.
Temperature scales differ in both their zero point and their step size, so converting needs an offset as well as a factor. This converter routes through kelvin — the absolute scale — which removes the offset problem: the input is converted to kelvin first, then out to the target scale. Kelvin and Rankine share absolute zero; Celsius and Fahrenheit do not, which is why 0 °C is 273.15 K.
Celsius → Kelvin
K = °C + 273.15
Fahrenheit → Kelvin
K = (°F − 32) ÷ 1.8 + 273.15
Kelvin → Rankine
°R = K × 1.8
Because the scales start at different zero points. Length has a shared zero, so 1 m is always 3.28 ft. Temperature needs the offset applied before the scaling, which is why °C to °F is ×1.8 then +32, not just ×1.8.
Nothing physical. 0 K (−273.15 °C, −459.67 °F) is the floor, so the calculator flags any input that converts to a negative kelvin value as impossible.