Convert pressure to liquid head or head back to pressure using specific gravity, with psi, bar, kPa, MPa, feet, meters, inches, and centimeters.

Static liquid column only; pipe friction and velocity head are not included.

SG is density ÷ 1,000 kg/m³ in this model. Presets are estimates; actual density varies with temperature and composition.

Optional settings

Calculator Operations Required Inputs
Convert Head and Specific Gravity to Pressure Head, Specific Gravity
Convert Pressure and Specific Gravity to Head Pressure, Specific Gravity
Convert Pressure and Head to Specific Gravity Pressure, Head

Pressure to Head Formula

The following formula is used to convert a pressure to head.

h ≈ p / (0.433 × SG)
  • Where h is the head (ft)
  • p is the static pressure difference (psi)
  • SG is the specific gravity of the fluid.

To calculate head from pressure, divide the pressure in psi by the product of 0.433 and the specific gravity to estimate head in feet. The calculator uses Δp = ρgh with g = 9.80665 m/s² and density = SG × 1,000 kg/m³.

PSI to Feet of Head Conversion Table (Water, SG = 1.00; 1 ft ≈ 0.433 psi)
Pressure (PSI) Head (ft H₂O)
1/160.144
⅛0.289
1/60.385
¼0.577
⅓0.770
⅜0.866
½1.155
⅝1.443
⅔1.540
¾1.732
⅞2.021
12.309
1¼2.887
1⅓3.079
1½3.464
1¾4.042
24.619
2½5.774
36.928
49.238
* Rounded to 3 decimals. Assumes water (SG = 1.00). Using the rounded reference factor: 1 ft ≈ 0.433 psi, so 1 psi ≈ 2.309 ft of head.

Pressure to Head Definition

Static pressure head is the height of an incompressible liquid column supporting a pressure difference: h = Δp/(ρg). This excludes pipe friction and velocity head.

Pressure to Head Example

How to convert pressure to head?

  1. First, determine the pressure.

    Measure the static pressure difference in PSI.

  2. Next, determine the specific gravity.

    Calculate or measure the specific gravity of the fluid.

  3. Finally, calculate the head.

    Calculate the head in feet using the equation above.

FAQ

What is a head?

A head is defined as the total height of a liquid column that exerts a certain pressure on the base of the liquid container by the fluid.