Enter the pressure in psi and flow rate in gallons per minute (gpm) to calculate hydraulic horsepower (HHP). Use the efficiency tab to find the motor or engine horsepower required to drive a real pump.

PSI to HP Calculator

Basic PSI to HP
Include Efficiency

Enter any 2 values to calculate the missing variable.

PSI ↔ HP Conversion Table (Flow = 10 GPM)
PSI to HP (at 10 GPM) HP to PSI (at 10 GPM)
500 psi = 2.917 hp1 hp = 171.4 psi
750 psi = 4.376 hp2 hp = 342.8 psi
1,000 psi = 5.834 hp3 hp = 514.2 psi
1,250 psi = 7.292 hp5 hp = 857 psi
1,500 psi = 8.752 hp7.5 hp = 1,285.5 psi
1,750 psi = 10.212 hp10 hp = 1,714 psi
2,000 psi = 11.668 hp15 hp = 2,571 psi
2,500 psi = 14.585 hp20 hp = 3,428 psi
3,000 psi = 17.502 hp25 hp = 4,285 psi
3,500 psi = 20.420 hp30 hp = 5,142 psi
Formulas: HP = (PSI x GPM) / 1714 and PSI = (HP x 1714) / GPM.
PSI ↔ HP Conversion Table (Flow = 20 GPM)
PSI to HP (at 20 GPM) HP to PSI (at 20 GPM)
500 psi = 5.834 hp2 hp = 171.4 psi
750 psi = 8.752 hp5 hp = 428.5 psi
1,000 psi = 11.668 hp7.5 hp = 642.8 psi
1,250 psi = 14.585 hp10 hp = 857 psi
1,500 psi = 17.502 hp15 hp = 1,285.5 psi
1,750 psi = 20.420 hp20 hp = 1,714 psi
2,000 psi = 23.336 hp25 hp = 2,142.5 psi
2,500 psi = 29.170 hp30 hp = 2,571 psi
3,000 psi = 35.004 hp40 hp = 3,428 psi
3,500 psi = 40.838 hp50 hp = 4,285 psi
Formulas: HP = (PSI x GPM) / 1714 and PSI = (HP x 1714) / GPM.

Psi to Horsepower Formula

hp = (psi * gpm) / 1714

hp = hydraulic horsepower | psi = pressure in pounds per square inch | gpm = flow rate in gallons per minute

The constant 1714 comes from unit conversions: 1 HP = 33,000 ft·lb/min; 1 gallon = 0.13368 ft³; 1 PSI = 144 lb/ft². Multiplied out: 33,000 / (144 x 0.13368) = 1,714.3. This means 1 hydraulic horsepower equals 1,714 psi·gpm.

Real-World Hydraulic HP Reference

Typical Hydraulic HP by Application
Equipment Typical PSI Typical GPM Hydraulic HP Range
Log splitter2,500–3,0002–52.9–8.8 hp
Skid steer loader3,000–3,50015–3026–61 hp
Mini excavator3,000–4,00015–2526–58 hp
Agricultural tractor2,000–3,00010–2012–35 hp
Industrial power unit1,000–3,0005–503–88 hp
High-pressure press5,000–10,0002–106–58 hp
Crane / lift3,000–4,00020–5035–117 hp
Values are approximate. HP = (PSI x GPM) / 1714. Add 15–20% for pump inefficiency when sizing motors.

Hydraulic HP vs. Required Motor HP

The formula gives theoretical hydraulic horsepower at 100% efficiency. Real pumps have mechanical losses, so the motor or engine must supply more than the hydraulic HP output. Divide hydraulic HP by pump efficiency to find required input power.

Pump Efficiency Reference (Motor HP Required per 10 HHP Needed)
Pump Type Typical Efficiency Motor HP per 10 HHP
Gear pump80–85%11.8–12.5 HP
Vane pump82–87%11.5–12.2 HP
Axial piston pump87–95%10.5–11.5 HP
Motor HP = Hydraulic HP / efficiency. Always size up to the next standard motor rating.

What is PSI?

PSI (pounds per square inch) measures hydraulic fluid pressure. It represents the force per unit area the pump exerts on the fluid. Most industrial hydraulic systems operate at 1,000 to 5,000 PSI. High-pressure circuits for presses or specialized equipment can exceed 10,000 PSI. Higher PSI produces more force from a given cylinder bore but increases heat generation and component wear.

What is Hydraulic Horsepower?

Hydraulic horsepower (HHP) is the power carried by pressurized fluid. It is distinct from shaft or motor horsepower: HHP is the theoretical power delivered to the hydraulic actuator, while shaft HP is what the engine or electric motor must supply to achieve it. Because all pumps have efficiency losses, shaft HP is always higher than HHP. A pump with 90% efficiency delivering 10 HHP requires 11.1 shaft HP from the motor.

Worked Example

Given: Pressure = 150 psi, Flow rate = 50 gpm

hp = (150 * 50) / 1714 = 7500 / 1714 = 4.376 hp

At 85% pump efficiency, the required motor HP: 4.376 / 0.85 = 5.15 HP. Select the next standard motor size (5.5 HP or 7.5 HP).