Not only are Celsius and Fahrenheit degrees different sizes (each Celsius degree covers more of the scale) they have different baselines. Fortunately, there are easier ways to convert temperatures ...

His competing scale measured temperature according to its impact on water, which freezes at 0C and boils at 100C. To convert from Fahrenheit to Celsius, simply subtract 32 and multiply by 0.5556 ...

Thankfully, Reddit user quaxon shared a dead-simple method for converting between Fahrenheit and Celsius in your head with no need for a calculator.