How do you convert feet of head to PSI?

Use PSI = feet of water × 0.4335 (at about 60°F). This calculator uses 0.4335 psi/ft as the default but also lets you adjust for water temperature.

What is 1 PSI in feet of water?

1 psi ≈ 2.31 ft of water at 60°F. We simply invert the 0.4335 psi/ft factor: ft = psi ÷ 0.4335.

Why does water temperature matter?

The pressure from a water column depends slightly on water density, which changes with temperature. For most plumbing work 60°F (15.6°C) is accurate enough, but in lab/industrial calculations you might want to pick the exact temperature.

Feet of Water to PSI Converter (ft H₂O → psi)

Reverse: PSI → Feet of Water

psi

Enter known pressure

Feet of water (ft H₂O)

ft = psi ÷ factor

Current factor:0.4335 psi per ft

1 psi in ft H₂O:2.306 ft

Quick table (60°F)

ft of water	psi	Notes
1 ft	0.4335	Base factor
5 ft	2.1675	Small elevation
10 ft	4.3350	Common pump calc
25 ft	10.8375	≈ 11 psi
50 ft	21.6750	Two-storey equivalent

Formula for feet of water to psi

psi = ft H₂O × 0.4335 (at ~60°F)

More generally:
psi = (ft × ρ × g) ÷ 144

where ρ is water density (lb/ft³), g = 32.174 ft/s², and 144 is in² per ft².

Why 0.4335?

It comes from the weight of a 1 ft column of water over 1 square inch. Most plumbing charts round this to 0.433 or even 0.434. This tool uses 0.4335 as a practical default.

FAQ

1. How accurate is this for hot water?

Hot water is slightly less dense, so it makes a little less pressure for the same height. Choose 212°F preset to see the effect — you’ll get around 0.338 psi/ft instead of 0.4335.

2. Can I use this for other liquids?

This page is specifically for water. For other liquids you need to scale by specific gravity (SG): psi(liquid) = ft × 0.4335 × SG.

3. Why do some references say 2.31 ft/psi?

That’s just the inverted factor: 1 ÷ 0.4335 = 2.306… Many charts round this to 2.31 ft of water per psi.