Enter the valve flow coefficient (CV) and the pressure differential (PSI) into the GPM from CV Calculator. The calculator will evaluate the GPM from CV. 

CV ⇄ GPM Calculator

Provide Specific Gravity and any two of the three remaining values to solve for the third.

GPM from CV Formula

The following two example problems outline the steps and information needed to calculate the GPM from CV.

GPM = CV * SQRT (P/SG)

Variables:

  • GPM is the GPM from CV (gallons per minute)
  • CV is the valve flow coefficient (CV) 
  • P is the pressure differential (PSI) 
  • SG is the specific gravity of the liquid (1 for water).

To calculate GPM from CV, multiply the valve coefficient by the square root of the pressure differential.

Valve Cv to GPM Conversion Table (Water at 60°F, SG = 1.00, ΔP = 1 psi)
Cv (unitless) Flow (GPM)
0.50.500
0.750.750
11.000
1.51.500
22.000
33.000
44.000
55.000
7.57.500
1010.000
1212.000
1515.000
2020.000
2525.000
3030.000
4040.000
5050.000
7575.000
100100.000
150150.000
* Rounded to 3 decimals. US customary: Q (GPM) = Cv × √(ΔP/SG). With SG = 1.00 and ΔP = 1 psi, Q = Cv.

How to Calculate GPM from CV?

The following steps outline how to calculate the GPM from CV.


  1. First, determine the valve flow coefficient (CV). 
  2. Next, determine the pressure differential (PSI). 
  3. Next, gather the formula from above = GPM = CV * SQRT (P).
  4. Finally, calculate the GPM from CV.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

valve flow coefficient (CV) = 2.5

pressure differential (PSI) = 30

GPM = CV * SQRT (P) = ?