Pressure Calculator
From a force on an area, or from a depth of fluid.
Work out Pressure. From a force on an area, or from a depth of fluid. Gravity is an input, not an assumption.
Standard gravity by definition. Local values run 9.78 to 9.83.
Pressure (kPa)
100
14.504 psi · 0.9869 atm
Pressure is force spread over area, which is why the area matters as much as the force. The same weight through a stiletto heel exerts far more pressure than through a flat sole, and that is the entire principle behind both snowshoes and drawing pins.
How the Pressure Calculator works
Pressure from a force spread over an area, or from a depth of fluid. Hydrostatic pressure depends on nothing but depth, density and gravity — the shape and width of the container are irrelevant, which is Pascal's result and the reason a hydraulic jack works.
Also known as: psi calculator · water pressure calculator · hydrostatic pressure calculator · pressure formula
Depth is all that matters
Hydrostatic pressure is ρgh — density, gravity, depth. Nothing about the container's shape or width appears in it.
A narrow pipe and a wide lake press equally hard at the same depth. This is Pascal's result, and it seems wrong until you notice that the water above any given point is supported by the walls as much as by the water below.
In practice
Ten metres of water is about 98 kPa, or 0.97 atmospheres — which is where the diving rule of thumb comes from. One atmosphere per ten metres is accurate to within a few percent.
Pressure is force spread over area, so the area matters as much as the force. The same person exerts far more pressure through a stiletto heel than a flat sole, which is the entire principle behind both snowshoes and drawing pins.
One standard atmosphere is 101,325 Pa exactly. That figure is a definition rather than a measurement, fixed by convention, so it is stated as exact here.
Frequently asked questions
How do I calculate pressure?
Divide force by area. 1,000 N over 100 cm² is 100 kPa, which is about one atmosphere.
How much pressure is 10 metres of water?
About 98 kPa, or 0.97 atmospheres. The diving rule of thumb — one atmosphere per ten metres — is accurate to within a few percent.
Does the width of a container change the pressure?
No. A narrow pipe and a wide lake at the same depth press equally hard. Only depth, fluid density and gravity matter.
How do I convert kPa to psi?
Divide by 6.895. So 100 kPa is 14.50 psi, and one standard atmosphere — 101.325 kPa — is 14.70 psi.
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<iframe src="https://www.thecalclibrary.com/embed/pressure-calculator" width="100%" height="640" style="border:1px solid #e2e8f0;border-radius:12px" loading="lazy" title="Pressure Calculator"></iframe>The only condition is that the credit line stays visible. It sits inside the frame, so you do not have to do anything to keep it.