Enter the total depth under the surface of the water and select whether the water is freshwater or saltwater. The calculate will evaluate and display the water pressure.

Water Pressure Formula

The following formula can be used to calculate the water pressure an object sees at a given depth.

P = p*g*h
  • Where P is the water pressure
  • p is the density of the fluid
  • g is the acceleration due to gravity
  • h is the depth of the object in the water

To calculate the water pressure, multiply the density of the fluid by the acceleration due to gravity, then multiply this result by the depth.

For fresh water, the density is 997.0474 kg/m^3

For salt water, the density is 1023.6 kg/m^3

Water Pressure Definition

Water pressure is the total pressure acting on an object in submerged water that arises from the water density and force of gravity.

Water Pressure Example

How to calculate water pressure?

  1. First, determine the density of the water.

    Determine if the water is fresh water or salt water.

  2. Next, determine the depth of the object.

    Determine the total depth the object is submerged at.

  3. Finally, calculate the water pressure.

    Use the equation above to calculate the water pressure.


What is water pressure?

Water pressure, also known as hydrostatic pressure, is the pressure an object sees while submerged in water due to the weight of the water around it.

Why is water pressure different for salt water and fresh water?

The pressure is different because the salt water is denser than fresh water and so weighs more per unit volume.

What is the acceleration due to gravity?

This is a constant 9.8 m/s^2 on Earth. This value would be different on other planets.

water pressure calculator
water pressure formula