Wind chill is calculated using the following formula: Wind Chill = 35.74 0.6215T – 35.75(V⁰.¹⁶) 0.4275T(V⁰.¹⁶). The wind chill is in degrees Fahrenheit, T is the air temperature, and V is the wind speed in miles per hour. Above is the official wind chill chart from the National Weather Service as of 2009.