How is hydrostatic pressure calculated?

Hydrostatic pressure is determined by the depth of the fluid column above the point in question, combined with the density of the fluid. The formula commonly used to calculate hydrostatic pressure at a certain depth is derived from the relationship between pressure, fluid density, gravitational acceleration, and depth. Specifically, the pressure at a given depth can be calculated using the formula:

Pressure (P) = Density (ρ) × Gravity (g) × Depth (h)

When using feet as the unit of depth and considering fresh water, the density is approximately 62.4 pounds per cubic foot, and the gravitational constant is about 32.2 feet per second squared. When rearranged for practical calculations, this gives a simplified representation where the pressure in psi (pounds per square inch) can be approximated as the depth in feet multiplied by 0.445.

This means that for every foot of depth in water, there is an increase in pressure of about 0.445 psi. As such, multiplying the depth in feet by 0.445 provides a direct method to calculate the hydrostatic pressure, making it the correct response.