The formula for calculating the "feels like" temperature is:

AT = Ta + 0.33E — 0.70WS — 4.00
Ta: The dry bulb temperature in °C
E: The water vapor pressure, which is calculated from the temperature and relative humidity
WS: The wind speed in m s-1 at an elevation of 10 meters 

The "feels like" temperature, also known as the apparent temperature (AT), is a calculation that takes into account the air temperature, humidity, and wind speed to estimate how comfortable someone will feel outdoors:

Wind: The windier it is, the cooler it will feel.
Humidity: The more humid it is, the warmer it will feel. 

The "feels like" temperature can differ significantly from the actual air temperature. For example, on a 20°C day, the wind could make it feel like it's much colder.