You have a temperature reading measured in Fahrenheit and need to convert it to Celsius.

public static double FtoC(double fahrenheit)
{
    return ((0.5/0.9) * (fahrenheit - 32));
}

This recipe makes use of the following Fahrenheit-to-Celsius temperature conversion equation:

TempCelsius = (5 / 9) * (TempFahrenheit - 32)

The Fahrenheit temperature scale is widely used in the United States. However, much of the rest of the world uses the Celsius temperature scale.