# Water Pressure Definition

In physics, water pressure can be defined as water flow from a tap or pipe. Whereas pressure is defined as the force applied perpendicular to an object's surface per unit area over which it's distributed. The SI unit used to determine pressure is Pascal (Pa). For instance, if a fire brigade car pulls the water to a specific distance, it needs a particular amount of water pressure.

**Table of Contents**

## Formula of Water Pressure

If you want to determine the pressure of water from pipes etc., you can use the formula listed below:

Water pressure = ρ g h

**Where,**

P = Pressure of water

g = Gravitational constant = 9.81 ms-2

ρ = Water density = 997 kg/m³

h = height (from the origin to where the water has to be delivered)

**Note:**

If you want to calculate the water pressure, you can use our Water Pressure Calculator.

### Example

For a more precise perception of water pressure, let us solve an example listed below:

Suppose a fire brigade has to pull the water to a height of 25m is to be filled with water. Then determine the needed amount of pressure used to flow the water to a specific amount.

**Given data**

h = 25m

ρ = 997 kg/m³

g = 9.81 ms^{-2}

**To Find**

Water pressure = ?

**Solution**

To determine the water pressure, we will use the formula listed below:

Water pressure = ρ g h

Putting values in the formula:

Water pressure = 997 x 9.81 x 25 = 244,514 Pa