The maximum water vapor that air can hold at 30°c is about 30 grams/cubic meter. if the humidity of the air is currently 6 grams/cubic meter at the same temperature, the relative humidity is %. nextreset

Relative humidity (RH) is the ratio of the partial pressure of water vapor to the equilibrium vapor pressure of water at a given temperature. Relative humidity depends on temperature and the pressure of the system of interest. To calculate we use the formula:

%RH = (actual vapor density / saturation vapor density) x 100%
%RH = (6 / 30) x 100%
%RH = 20%