🏗️ Pressure Head Converter
10-meter water tower = ~1 bar at bottom. Divers know 10 m depth adds another bar. Bridges hydrostatic pressure and column height.
Last updated — conversions use exact ISO unit definitions.
How it works
Pressure head is pressure expressed as the height of a water column. The formula is P = ρgh — density × gravity × height. For water at room temperature, 1 meter of water ≈ 9.80665 kPa ≈ 0.0967 atm ≈ 1.42 psi. Feet of water: 1 ft H₂O ≈ 2.989 kPa ≈ 0.433 psi.
This is essential for plumbing and hydraulics: a pump needs enough head to overcome the elevation difference plus friction losses. If your bathroom is 5 meters above the water tank, you need at least 49 kPa (0.48 atm, 7.1 psi) just to push water up there.
The conversion factor 1 m H₂O = 0.0981 bar = 9.80665 kPa is the one to memorize. Mercury is 13.6× denser than water, so 1 mmHg = 13.6 mmH₂O ≈ 133.3 Pa.
Hydrostatic pressure formula
P = ρgh. Water density ≈ 1000 kg/m³, gravity = 9.80665 m/s². 1 m of water = 0.098 bar. Mercury is 13.6× denser — that's why 760 mmHg = 1 atm = 10.33 m water.
How accurate are these conversions?
All conversions use ISO 80000 standard unit definitions. For example, 1 inch = 2.54 centimeters exactly by international agreement.
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The result table scrolls horizontally. The headline pair above shows the most commonly requested conversion.
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