# Relative Humidity

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

Relative humidity, abbreviated as RH, a dimensionless number, is a measure of the amount of moisture in the air with respect to the temperature.

## Relative Humidity formulas

 $$\large{ RH = 100 \; \frac{e}{e_s} }$$ $$\large{ RH = 100 \; \left( \frac{ 112 \; - \; 0.1 \; T \; + T_d }{ 112 \; + \; 0.9 \; T } \right)^8 }$$

### Where:

$$\large{ RH }$$ = relative humidity

$$\large{ e }$$ = actual vapor pressure

$$\large{ T_d }$$ = dewpoint temperature

$$\large{ e_s }$$ = saturated vapor pressure

$$\large{ T }$$ = temperature