Feet of Head to PSI Calculator

SettingsSettings for this calculationUS

Market

Imperial · sales tax

Head (ft)

The vertical height of the water column, in feet.

Measure the vertical rise only — horizontal run adds friction loss, not static head. From the water surface to the highest outlet is the static head; the pump must overcome that plus friction plus any residual pressure you need at the outlet.

Static pressure

43.35 psi

High confidence

1 ft of water at 4 °C = 62.428 lb/ft³ ÷ 144 in²/ft² ≈ 0.4335 psi. Equivalently, 2.31 ft per psi. Assumes clean water at 4 °C. For any other fluid, multiply by its specific gravity.

Head entered: 100 ft
Pressure: 43.35 psi
Metric equivalent: 43.35 psi
Bar: 2.99 bar

Then change the inputs to see how far the answer moves.

Show calculation logic

How this was calculated

Formula source(s)

Water density 62.428 lb/ft³ at 4 °C — NIST/CRC standard reference
Hydrostatic pressure p = ρgh; 1 psi ≈ 2.31 ft of water column

Inputs used

Head (ft): 100

Intermediate steps

Head entered: 100 ft
Pressure: 43.35 psi
Metric equivalent: 43.35 psi
Bar: 2.99 bar

Final result43.35 psi

Confidence note: 1 ft of water at 4 °C = 62.428 lb/ft³ ÷ 144 in²/ft² ≈ 0.4335 psi. Equivalently, 2.31 ft per psi. Assumes clean water at 4 °C. For any other fluid, multiply by its specific gravity.

What this calculation does not cover

This is static head only. Friction loss through pipe, fittings, valves and the meter, and the residual pressure a fixture, shower or sprinkler head needs to work, are all excluded. Total dynamic head is static head plus those two, and sizing a pump on this figure alone is how a system ends up short at the top outlet.
The factor assumes clean water at 4 °C and the result does not scale for any other fluid. Glycol, brine, fuel oil and hot circulating water all differ in density, so multiply by specific gravity yourself — a strong glycol charge reads low here, hot heating water reads high.
It describes a column at rest. Velocity head, a pump running near shut-off, thermal expansion in a closed circuit and water hammer on valve closure can all push real system pressure well above this figure, and it is the peak, not the static value, that splits a fitting or lifts a relief valve.
Only the water column's own pressure is counted. Fill pressure in a sealed heating circuit, an expansion vessel's charge, a booster set's outlet pressure or gas pressure above the water in a closed tank all add on top of this number and none of them are in it.
This is not a pressure rating check and not a pump selection. It says nothing about the pressure class of the pipe, fittings, cylinder or appliance at the bottom of the lift, and nothing about NPSH available at a pump suction — cavitation is governed by suction conditions, not by the discharge head being converted here.

Add the equipment this sizes

This result is a specification — 43.35 psi — not a quantity. Put the thing it sizes into your project: how many, what you call it, and your supplier’s price.

QtyItemPrice each ($)

Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.

Sources checked 2026-09-02 · in the site-wide review of 2026-09-06 · v1.0.1

Regulatory standards & verification citations2

Water density 62.428 lb/ft³ at 4 °C — NIST/CRC standard reference
Hydrostatic pressure p = ρgh; 1 psi ≈ 2.31 ft of water column

Cite this page

Your workspace

Most jobs need more than one number. Add the calculators you need next and they open right here, underneath this one — your figures stay on screen and nothing is lost to a page change.

Pumps are catalogued in feet of head; gauges and fixtures are rated in psi. Converting between them is the moment a pump curve becomes a check you can carry out with a gauge, and it is where a system that looked adequate on paper turns out to be 15 psi short at the top floor.

Now that you have the number

These guides cover the work this quantity is for — the first ones run this calculator inside the section that raises the question.

Matching a Shower to the Water Supply You Haveuses this calculator

A shower valve carries a minimum working pressure on its box, and a loft-fed house rarely has it — so four measurements decide the product, not the showroom.

Private Well Supply and Pressure Tanksuses this calculator

How drawdown volume and pump cycle rate govern every sizing, setting and commissioning decision on a private well water supply.

Putting a Rising Main Into a Tall Buildinguses this calculator

Height alone decides whether a fire main can stay empty, and the wet answer arrives with a pump, a tank and a rated room nobody costed.

Head (ft)	Static pressure (psi)
10	4.34
20	8.67
50	21.7
100	43.4
200	86.7
500	217
1,000	434

Head (ft)

Static pressure (psi)

4.34

8.67

21.7

100

43.4

200

86.7

500

217

1,000

434

Frequently asked questions

Why 2.31 feet per psi and not 2.3?

2.31 comes from water at 4 °C, where it is densest. The rounder 2.3 is a jobsite shorthand. Over a 300 ft lift the difference is about 2 psi — immaterial for a domestic pump, and worth carrying properly on a tall building or a long rising main.

Does the pipe diameter change the pressure?

Not the static pressure. A column of water exerts pressure by its height alone, so a 1 in pipe and a 12 in pipe at the same height read the same. Diameter matters for flow and friction loss, which is a separate and often larger part of the pump's duty.

What about a liquid that is not water?

Scale by specific gravity. Glycol at 1.04 gives 4% more pressure per foot; diesel at about 0.85 gives 15% less. This calculator assumes water — using it for a heating system with a strong glycol charge will under-read.

Is this the pressure my pump needs to produce?

It is one part of it. Total dynamic head is static head plus friction loss through pipe, fittings and valves, plus any pressure required at the outlet. Sizing on static head alone is a common way to end up with a pump that will not deliver at the top of the building.