Calculate hydraulic horsepower from pressure difference and US gallons per minute, or solve for PSI, flow, shaft power and pump efficiency. A separate boost mode provides only an idealized engine pressure-ratio comparison.
| PSI to HP (at 10 GPM) | HP to PSI (at 10 GPM) |
|---|---|
| 500 psi = 2.917 hp | 1 hp = 171.4 psi |
| 750 psi = 4.376 hp | 2 hp = 342.8 psi |
| 1,000 psi = 5.834 hp | 3 hp = 514.2 psi |
| 1,250 psi = 7.293 hp | 5 hp = 857 psi |
| 1,500 psi = 8.751 hp | 7.5 hp = 1,285.5 psi |
| 1,750 psi = 10.210 hp | 10 hp = 1,714 psi |
| 2,000 psi = 11.669 hp | 15 hp = 2,571 psi |
| 2,500 psi = 14.586 hp | 20 hp = 3,428 psi |
| 3,000 psi = 17.503 hp | 25 hp = 4,285 psi |
| 3,500 psi = 20.420 hp | 30 hp = 5,142 psi |
| Formulas: HP = (PSI x GPM) / 1714 and PSI = (HP x 1714) / GPM. | |
| PSI to HP (at 20 GPM) | HP to PSI (at 20 GPM) |
|---|---|
| 500 psi = 5.834 hp | 2 hp = 171.4 psi |
| 750 psi = 8.751 hp | 5 hp = 428.5 psi |
| 1,000 psi = 11.669 hp | 7.5 hp = 642.75 psi |
| 1,250 psi = 14.586 hp | 10 hp = 857 psi |
| 1,500 psi = 17.503 hp | 15 hp = 1,285.5 psi |
| 1,750 psi = 20.420 hp | 20 hp = 1,714 psi |
| 2,000 psi = 23.337 hp | 25 hp = 2,142.5 psi |
| 2,500 psi = 29.172 hp | 30 hp = 2,571 psi |
| 3,000 psi = 35.006 hp | 40 hp = 3,428 psi |
| 3,500 psi = 40.840 hp | 50 hp = 4,285 psi |
| Formulas: HP = (PSI x GPM) / 1714 and PSI = (HP x 1714) / GPM. | |
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psi to Horsepower Formula
hp = hydraulic horsepower | psi = pressure in pounds per square inch | gpm = flow rate in US gallons per minute
The constant 1714 comes from unit conversions: 1 HP = 33,000 ft·lb/min; 1 US gallon = 231 cubic inches; 1 PSI = 144 lb/ft². The exact unit ratio is 33,000 × 12 / 231 = 1,714.285714…. This calculator and the tables use the conventional rounded factor 1714; results are approximate.
Illustrative Hydraulic HP Calculations
| Example label | Assumed PSI | Assumed US GPM | Hydraulic HP Range |
|---|---|---|---|
| Log splitter | 2,500–3,000 | 2–5 | 2.9–8.8 hp |
| Skid steer loader | 3,000–3,500 | 15–30 | 26–61 hp |
| Mini excavator | 3,000–4,000 | 15–25 | 26–58 hp |
| Agricultural tractor | 2,000–3,000 | 10–20 | 12–35 hp |
| Industrial power unit | 1,000–3,000 | 5–50 | 3–88 hp |
| High-pressure press | 5,000–10,000 | 2–10 | 6–58 hp |
| Crane / lift | 3,000–4,000 | 20–50 | 35–117 hp |
| Illustrative assumed inputs only, not equipment specifications or operating limits. HP = (PSI x US GPM) / 1714. Use the manufacturer’s actual pressure, flow and overall efficiency at the operating point. | |||
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 Type | Assumed Efficiency | Motor HP per 10 HHP |
|---|---|---|
| Gear pump | 80–85% | 11.8–12.5 HP |
| Vane pump | 82–87% | 11.5–12.2 HP |
| Axial piston pump | 87–95% | 10.5–11.5 HP |
| Shaft HP = hydraulic HP / efficiency as a fraction. These assumed efficiencies are examples, not ratings by pump type. Consult actual operating data and include applicable starting, duty and service requirements. | ||
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. For a real pump with losses, shaft input power exceeds its hydraulic output; at ideal 100% efficiency they are equal. 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
At 85% overall pump efficiency, shaft input power is approximately 4.376 / 0.85 = 5.15 HP. Final motor selection also requires actual starting, duty, service and manufacturer requirements.
