In short: divide pressure in psi by 0.43353 (or multiply by 2.3067) to get feet of head for water at nominal density. At 20 °C, 50 psi equals about 115.5 ft (35.2 m) of head. Warmer water is slightly less dense, so it takes a touch more height to produce the same pressure — use the calculator above for the exact figure at your temperature.
These figures are planning aids based on published density data. For pump selection, tank design or code-driven work, confirm with a licensed engineer.
How to convert pressure to head
Pressure and head describe the same physical quantity in two different units. Head is the height of a column of water that would, by its own weight, produce a given pressure at the bottom. The relationship comes straight from hydrostatics:
This calculator converts your pressure reading to pascals, looks up the density of water at the temperature you entered, and returns the head in feet, meters, inches and centimeters. For everyday plumbing questions the standard shortcut — divide psi by 2.31 — is close enough. This tool uses the exact, temperature-corrected density instead, so the number matches what a lab-grade gauge would actually read.
Worked example. Take 50 psi at 20 °C. Converted, 50 psi is 344,738 Pa. Water at 20 °C has a density of 998.20 kg/m³, so ρg = 998.20 × 9.80665 = 9,789.0 Pa per meter of head. Divide: 344,738 ÷ 9,789.0 = 35.22 m, which is 115.5 ft. That division is all the calculator is doing — the work is in getting the density right for the temperature.
Need the other direction? If you have a head or lift and want the equivalent pressure, use the Head to Pressure Calculator instead — it runs the same formula in reverse.
Why temperature changes the answer
The pressure a column of water produces depends on how much mass is packed into it — its density — not just its height. Warm water spreads out and is less dense, so it takes a slightly taller column to produce the same pressure at the bottom. Water reaches its maximum density at about 4 °C; above that point density drops steadily, by roughly 4% between 4 °C and 100 °C.
Under the hood, this calculator uses the Kell equation, the standard polynomial fit for the density of air-free water between 0 °C and 150 °C at one atmosphere, the same equation used across this site's density and weight calculators. You can read the full method on our methodology page.
Pressure to head, at a glance
Head in feet and meters for common pressures, using fresh water at 20 °C (68 °F) — the calculator's default. Recalculate above for other temperatures or units.
| Pressure (psi) | Head (ft) | Head (m) |
|---|---|---|
| 10 psi | 23.11 | 7.04 |
| 20 psi | 46.22 | 14.09 |
| 30 psi | 69.32 | 21.13 |
| 40 psi | 92.43 | 28.17 |
| 50 psi (worked example) | 115.54 | 35.22 |
| 60 psi (typical city main) | 138.65 | 42.26 |
| 80 psi | 184.86 | 56.35 |
| 100 psi | 231.08 | 70.43 |
Quick reference: other pressure units
Head equivalent of 1 unit of pressure for fresh water at 20 °C. The calculator handles any combination of pressure and temperature directly.
| Pressure | Head (ft) | Head (m) |
|---|---|---|
| 1 psi | 2.311 | 0.704 |
| 1 bar | 33.52 | 10.22 |
| 1 atm (101.325 kPa) | 33.96 | 10.35 |
| 1 kPa | 0.3352 | 0.1022 |
Worked examples
Typical home supply, 50 psi
115.5 ft
A common residential water pressure of 50 psi is equivalent to about 115.5 ft (35.2 m) of head at 20 °C — roughly the height of an 11-story standpipe.
City main pressure, 60 psi
138.6 ft
A municipal main running at 60 psi corresponds to about 138.6 ft (42.3 m) of head — the figure a booster pump or elevated tank would need to reach to match it.
High-pressure irrigation, 100 psi
231.1 ft
A pressurized irrigation line at 100 psi equals about 231.1 ft (70.4 m) of head — well beyond what gravity alone could supply from any practical elevated tank.
What else affects the result
Dissolved salts. Seawater is about 2–3% denser than fresh water, so the same pressure produces slightly less head. Switch the water type above if you are converting for a seawater, brine or pool-chemical system.
Elevation and atmospheric baseline. This calculator works with gauge pressure, so local atmospheric pressure and altitude don't enter the calculation. If you need to add elevation change on top of this head, see the Elevation Head Calculator.
Friction and velocity losses. This is a static conversion — it assumes no flow. A pump moving water through pipe also has to overcome friction head and velocity head; combine all three to size a pump correctly with the Total Dynamic Head Calculator.
Frequently asked questions
How do I convert psi to feet of head?
Divide the pressure in psi by 0.43353, or multiply it by 2.3067, to get feet of head for water at standard density. This calculator performs the same conversion using the exact density of water at whatever temperature you enter, so results stay accurate to within a few thousandths of a foot.
What is the divide-by-2.31 rule of thumb?
Plumbers and pump techs commonly divide psi by 2.31 (or multiply by 0.433) to estimate feet of head, using a nominal water density (specific gravity 1.000). It is accurate to within about 0.2% for most jobs. This calculator uses the true, temperature-corrected density instead, for an exact figure.
Does water temperature change the pressure-to-head conversion?
Slightly. Warmer water is less dense, so the same pressure produces a marginally taller column of it. Between 4 °C and 100 °C the effect is under 4%, small enough to ignore for everyday plumbing but worth including for engineering-grade precision.
Is this gauge pressure or absolute pressure?
Gauge pressure — the reading shown on a typical pressure gauge, measured relative to atmospheric pressure. Household water pressure, pump discharge pressure and irrigation pressure are almost always reported this way.
What is the difference between pressure head and elevation head?
Pressure head is the height of water column that would produce a given pressure. Elevation head is simply the vertical distance between two points in a system. Both are measured in the same units and are added together, along with velocity head and friction head, to find the total dynamic head a pump must overcome.
Sources & references
- Streeter, V. L., & Wylie, E. B. Fluid Mechanics. McGraw-Hill.
- Kell, G. S. (1975). Density, thermal expansivity, and compressibility of liquid water from 0° to 150 °C. Journal of Chemical & Engineering Data, 20(1), 97–105.
- National Institute of Standards and Technology (NIST). Thermophysical Properties of Fluid Systems.
John Mac, PE
Water Systems Specialist · Austin, Texas
Texas-licensed Professional Engineer with 13+ years in residential water systems and 180+ completed projects. Writes and reviews the calculators on watercalculator.us. Read full bio
Texas PE (2016) · BS Civil Engineering, Hydraulics (2013)