Enter your fluid type, depth, and fluid density to calculate the hydrostatic pressure at that point. You can also include surface pressure (atmospheric or custom) for total absolute pressure. The calculator returns gauge pressure, absolute pressure, and a visual breakdown using the formula p = ρ × g × h + p₀.
Absolute Pressure (p)
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Gauge Pressure (ρgh)
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Absolute Pressure
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Absolute Pressure
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Absolute Pressure
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Absolute Pressure
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Hydrostatic pressure is the pressure exerted by a fluid at rest due to the weight of the fluid above a given point. It increases with depth because there is more fluid above pressing down. Unlike dynamic pressure (which depends on fluid motion), hydrostatic pressure depends only on depth, fluid density, and gravitational acceleration — not on the size or shape of the container.
The hydrostatic pressure formula is p = ρ × g × h + p₀, where ρ is the fluid density (kg/m³), g is gravitational acceleration (9.8066 m/s²), h is the depth below the surface (m), and p₀ is the pressure at the fluid's surface (e.g. atmospheric pressure). The term ρgh gives gauge pressure, and adding p₀ gives absolute pressure.
For pure water (density ≈ 1000 kg/m³) at 2 m depth: gauge pressure = 1000 × 9.8066 × 2 ≈ 19,613 Pa (about 19.6 kPa). Adding standard atmospheric pressure (101,325 Pa), the absolute pressure at the bottom is approximately 120,938 Pa, or about 1.19 atm.
Gauge pressure measures the pressure relative to atmospheric pressure — it tells you how much extra pressure a fluid exerts beyond what the atmosphere already provides. Absolute pressure is the total pressure including the atmospheric (surface) pressure. Absolute pressure = gauge pressure + surface pressure.
No — hydrostatic pressure at a given depth depends only on the fluid density, gravitational acceleration, and depth. This is a key principle: a narrow test tube and a wide swimming pool filled with the same fluid to the same depth will have identical hydrostatic pressure at the bottom.
Water pressure in a supply system is largely determined by the height of the water source above the outlet (the hydraulic head). Raising the water tank or reservoir increases the effective depth (h) and thus the pressure. Pressure-boosting pumps can also increase the surface pressure p₀ applied to the system.
The Challenger Deep in the Mariana Trench reaches approximately 10,935 m depth. Using seawater density (~1025 kg/m³) and standard gravity, the gauge pressure there is roughly 1025 × 9.8066 × 10935 ≈ 109.9 MPa (about 1084 atm or 15,940 psi) — more than 1,000 times standard atmospheric pressure.
Yes, as long as you know the density of the gas. For gases, density varies significantly with pressure and temperature (unlike most liquids), so this calculator is most accurate for liquids or for gas columns where density is approximately constant. For precise gas column calculations, a compressible fluid model is recommended.