Enter the total head (ft) and the specific gravity into the calculator to determine the Pressure From Head. 

Head to Pressure Calculator

Enter any 2 values to calculate the missing variable

Pressure From Head Formula

The following formula is used to calculate the Pressure From Head. 

P = .433*H*SG
  • Where P is the Pressure From Head (psi)
  • H is the total head (ft) 
  • SG is the specific gravity 

To calculate pressure from head, multiply the head by .433, then multiply again by the specific gravity.

Feet of Head to Pressure Conversion Table (Specific Gravity, SG = 1.00)
Head (ft) Pressure (psi) bar kPa MPa
10.4330.0302.9880.003
20.8670.0605.9750.006
31.3000.0908.9630.009
41.7330.12011.9510.012
52.1670.14914.9390.015
62.6000.17917.9260.018
83.4670.23923.9020.024
104.3330.29929.8770.030
125.2000.35935.8530.036
156.5000.44844.8160.045
208.6670.59859.7550.060
2510.8330.74774.6930.075
3013.0000.89689.6320.090
4017.3331.195119.5090.120
5021.6671.494149.3860.149
6026.0001.793179.2640.179
8034.6672.390239.0180.239
10043.3332.988298.7730.299
15065.0004.482448.1590.448
20086.6675.975597.5460.598
* Rounded to 3 decimals. Assumes SG = 1.00 (water). Formula: P(psi) = H(ft) × 62.4 / 144 ≈ H × 0.4333. Unit conversions: 1 psi = 6.89476 kPa = 0.0689476 bar = 0.00689476 MPa.

How to Calculate Pressure From Head?

The following two example problems outline how to calculate the Pressure From Head.

Example Problem #1:

  1. First, determine the total head (ft). In this example, the total head (ft) is given as 1235.
  2. Next, determine the specific gravity. For this problem, the specific gravity is given as 40.
  3. Finally, calculate the Pressure From Head using the equation above: 

P = .433*H*SG

Inserting the values from above and solving the equation with the imputed values gives: 

P = .433*1235*40 = 21390.2 (psi)


Example Problem #2: 

Using the same process as above, first define the variables required by the formula. In this case, these values are:

total head (ft) = 55

specific gravity = 125

Entering these values yields:

P = .433*55*125 = 2976.875 (psi)