Water Pressure Calculator

Calculate hydrostatic pressure by depth and fluid density.

1. Dive Depth (h)
Meters (m)
2. Fluid Density (ρ)
3. Pressure Type
Total Pressure
100.55
Kilopascals (kPa)
0.99 Atmospheres (atm)
14.58 Pounds / Sq. In. (psi)
P = (1025) × (9.81) × (10) = 100,552 Pa
10m

Understanding Hydrostatic Pressure

Water pressure increases the deeper you go because of the weight of the water above pushing down. The formula to calculate this is:

P = ρ · g · h

  • P (Pressure): Measured in Pascals ($Pa$).
  • ρ (Rho - Density): The density of the fluid. Saltwater ($\approx 1025 \, kg/m^3$) is denser than freshwater ($\approx 1000 \, kg/m^3$), meaning it exerts more pressure at the same depth.
  • g (Gravity): Earth's gravitational pull ($9.81 \, m/s^2$).
  • h (Height/Depth): The distance below the surface in meters.

Gauge vs. Absolute Pressure: Gauge pressure only accounts for the weight of the water. Absolute pressure adds the weight of the Earth's atmosphere pushing down on the surface of the water (roughly $101,325 \, Pa$ or $1 \, atm$).