Hydrostatic Pressure Calculator
P = ρgh, in gauge and absolute.
Work out Hydrostatic Pressure. P = ρgh, in gauge and absolute. Shows the working, not just the answer.
Gauge pressure
98,066.5 Pa
199,391.5 Pa absolute · 1.968 atm
P = ρgh, and the shape of the container is irrelevant — a narrow tube and a wide lake give the same pressure at the same depth. That is the hydrostatic paradox, and it is why a tall thin standpipe can burst a tank. Roughly every 10 m of water adds one atmosphere. Gauge pressure ignores the air above; absolute includes it, and which one a gauge reads is a frequent source of confusion in diving and in plant instrumentation.
How the Hydrostatic Pressure Calculator works
Enter density and depth for the pressure, reported both as gauge and absolute. The shape of the container makes no difference — only the depth does, which is the part that surprises people.
Also known as: water pressure at depth calculator · pressure at depth formula · gauge vs absolute pressure calculator · fluid pressure calculator
Frequently asked questions
How do I calculate pressure at depth?
P = ρgh for gauge pressure. Add atmospheric pressure for absolute. Ten metres of water is very close to one extra atmosphere.
Does the shape of the container matter?
No, and this is the hydrostatic paradox. A narrow tube and a wide lake give identical pressure at identical depth, which is why a tall thin standpipe can burst a wide tank.
What is the difference between gauge and absolute pressure?
Gauge ignores the atmosphere and reads zero at the surface; absolute includes it and reads about 101 kPa there. Most instruments read gauge, and mixing the two is a common and expensive error.
How deep before pressure becomes dangerous?
For diving, the pressure itself is survivable far deeper than the physiological effects are. The limits come from gas behaviour under pressure rather than from crushing, which is why depth limits are about breathing mixtures.
Put this calculator on your own site
Free to use, on any site, commercial or not. Paste this where you want it to appear. It is a plain iframe, so it works in WordPress, Squarespace, Wix, Webflow, Ghost and anything else that accepts HTML.
<iframe src="https://www.thecalclibrary.com/embed/hydrostatic-pressure-calculator" width="100%" height="640" style="border:1px solid #e2e8f0;border-radius:12px" loading="lazy" title="Hydrostatic Pressure Calculator"></iframe>
<p style="font:13px/1.5 system-ui,sans-serif;margin:6px 0 0;color:#64748b">Powered by <a href="https://www.thecalclibrary.com/hydrostatic-pressure-calculator" style="color:#64748b">Hydrostatic Pressure Calculator</a> from The Calc Library</p>The only condition is that the credit line below the frame stays in place. That one line is what pays for the tool being free — it is how anyone else finds it.