Feet of Water to PSI Calculator

Feet of Water to PSI Calculator

Pressure Result

Pressure (PSI) Pounds per Square Inch
Formula: $$\text{PSI} = \text{Head (ft)} \times \text{Factor}$$ (Standard water density factor is $0.433 \text{ PSI/ft}$)

What Does "Feet of Water to PSI" Mean?

  • Feet of Water (Head): This is the height of a column of water. Imagine a vertical tube filled with water—its height determines the pressure at the bottom.
  • PSI (Pounds per Square Inch): This is the actual pressure measurement that tells you how much force the water exerts over one square inch of area.

The taller the water column, the higher the pressure at its base. That’s why tall water towers or elevated tanks create usable pressure in plumbing systems without pumps.

The Basic Formula

The conversion is simple:

[
\text{PSI} = \text{Feet of Water} \times \text{Conversion Factor}
]

For most situations:

  • Standard Water at Room Temperature: 1 foot of water ≈ 0.433 PSI
  • Hot Water (140°F):0.431 PSI/ft (slightly less dense)
  • Salt Water:0.439 PSI/ft (denser than fresh water)

This small variation comes from changes in water density. Our calculator includes these factors, so you don’t have to guess.

How the Feet of Water to PSI Calculator Works

The calculator simplifies the process:

  1. Enter the water height (feet).
    Example: 10 feet of water.
  2. Select the type of water.
    Choose standard, hot water, or salt water.
  3. Click "Convert."
    The tool instantly shows you the pressure in PSI.

Example Calculation:

  • 10 feet of water × 0.433 (standard factor) = 4.33 PSI

That’s it—no manual math needed.

Why Is This Conversion Important?

This isn’t just a numbers game—it has many real-world uses:

  • Plumbing and Water Supply: Ensures your fixtures get enough pressure.
  • Pump Sizing: Helps in selecting the right pump for wells or irrigation.
  • Engineering & HVAC: Used in hydronic systems and boiler design.
  • Aquariums & Ponds: Keeps water pressure safe for tanks and filters.
  • Firefighting Systems: Water towers and hydrant pressure rely on this principle.

Key Benefits of Using This Calculator

Fast and Accurate: No manual math errors.
Customizable: Choose between water types for precise results.
Beginner-Friendly: Plain input fields, clear outputs.
Practical: Saves time for engineers, contractors, or even hobbyists.

Handy Reference Conversion

Here’s a quick cheat sheet:

Feet of WaterApprox. PSI (Standard Water)
1 ft0.433 PSI
5 ft2.165 PSI
10 ft4.33 PSI
25 ft10.83 PSI
50 ft21.65 PSI
100 ft43.3 PSI

This shows why even a small change in height can significantly impact water pressure.