Calculate hydraulic horsepower from flow rate (GPM or L/min) and pressure (PSI or bar), plus pump shaft HP, kW, estimated pump loss, and an illustrative motor-size list.

Enter delivered flow and pressure rise across the pump.

Steady-state estimate using pump pressure rise. Pump efficiency defaults to 85%; sizing margin defaults to 0%. Shaft power excludes electric-motor losses.

Optional settings

Blank means no added margin.

Related Calculators

Hydraulic Horsepower Formula

HHP = P × Q / (12000 / 7)

Variables:

  • HHP is the Hydraulic Horsepower
  • P (psi) is the pressure rise across the pump
  • Q (US GPM) is the delivered flow rate

To estimate hydraulic horsepower, multiply pressure rise in psi by delivered US gallons per minute, then divide by approximately 1714. The calculator uses the full unit-derived divisor 12000/7 (approximately 1714.285714). Shaft power is hydraulic power divided by overall pump efficiency; electric-motor losses are separate.

How to Calculate Hydraulic Horsepower?

The following steps outline how to calculate the Hydraulic Horsepower.

  1. First, determine the pressure. 
  2. Next, determine the flow rate. 
  3. Next, use HHP = P * Q / (12000/7), with US GPM and psi.
  4. Finally, calculate the Hydraulic Horsepower.
  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.

pressure rise = 71 psi

flow rate = 32 US GPM; hydraulic power is approximately 1.3253 hp before pump losses.

FAQ

What is Hydraulic Horsepower?

Hydraulic Horsepower (HHP) is a measure of the power generated within a hydraulic system. It is calculated based on the pressure and flow rate of the fluid in the system.

Why is the number 1714 used in the formula for calculating Hydraulic Horsepower?

1714 is the rounded US-gallon/mechanical-horsepower conversion divisor. The full divisor is 12000/7, approximately 1714.285714. For metric inputs, fluid power in kW equals bar times L/min divided by 600.

Can Hydraulic Horsepower be used to measure the efficiency of a hydraulic system?

While Hydraulic Horsepower itself is a measure of power, it can indirectly indicate the efficiency of a hydraulic system when compared with the input power to the system. However, for a direct measure of efficiency, hydraulic motor efficiency calculations are more appropriate.

How does the flow rate affect the Hydraulic Horsepower of a system?

The flow rate directly affects the Hydraulic Horsepower of a system. An increase in flow rate, while keeping pressure constant, will result in an increase in Hydraulic Horsepower, illustrating the direct relationship between these variables in the power generation of hydraulic systems.