Enter the partial pressure of water vapor and the total pressure into the calculator to determine the specific humidity.

- Vapor Pressure Calculator (Solvent/Solution)
- Humidity Ratio Calculator
- Relative Humidity Calculator
- Heat Index Calculator

## Specific Humidity Formula

The following equation can be used to calculate a specific humidity.

SH = (.622 * P / ( P – Pw ) ) * 100

- Where SH is the specific humidity (%)
- P is the total pressure
- PW is the partial pressure of water vapor

## Specific Humidity Definition

Specific humidity is defined as the ratio of the humidity of the air to the absolute water vapor pressure of the air.

## Specific Humidity Example

How to calculate specific humidity?

**First, determine the total pressure.**Meausre the total pressure of the air.

**Next, determine the water vapor pressure.**Calculate the partial pressure of water vapor.

**Finally, calculate the specific humidity.**Using the equation above, calculate the specific humidity.

## FAQ

**What is specific humidity?**

Specific humidity is a measure of the humidity of air with respect to the ratio of the water vapor pressure to the total pressure.

**What is the partial pressure of water vapor?**

The partial pressure of water is the pressure that the water vapor contributes to the overall pressure of the air.