How to use this calculator
- Enter target force. Enter the cylinder output force you need.
- Enter bore and rod. Bore sets piston area; rod diameter is subtracted for pull force.
- Choose the stroke. Push uses full piston area, pull uses annulus area.
- Set efficiency. Use 1.0 for theoretical pressure or derate for friction and pressure losses.
How it works
Required hydraulic pressure is target force divided by working area:
P = F / A
On the push stroke, A = πB²/4. On the pull stroke,
A = π(B² - d²)/4 because the rod diameter d removes area
from the bore B. The practical pressure divides by the efficiency
factor, so P_required = F / (A·η).
Worked example
Verified against the live calculator
To get 25 kN from a 50 mm bore cylinder on push, piston area is
1963 mm². The theoretical pressure is
25000 / 1963 = 12.7 MPa, or about 127 bar. With a
0.90 efficiency factor, required pressure rises to about 142 bar.
Frequently asked questions
How do you calculate hydraulic pressure from force?
Use P = F/A, where F is the target force and A is the working piston area. For a push stroke A is the full bore area. For a pull stroke A is the annulus area after subtracting the rod area.
Why does pull stroke need more pressure?
The rod removes area on the retract side, so the same force has to be produced by a smaller annulus area. Smaller area means higher required pressure.
What is the efficiency factor?
It derates the theoretical pressure for seal friction, back pressure and pressure loss. Use 1.0 for ideal pressure, or 0.85-0.95 for a more practical first estimate.
Does this replace checking cylinder ratings?
No. Use it for first-pass sizing, then check cylinder pressure rating, rod buckling, mounting strength, side load, hose pressure drop and relief-valve settings.
Can I use psi instead of bar?
Yes. Use the SI/Imperial toggle in the header. The calculator accepts force, length and pressure outputs in either unit system.
Method & assumptions
- Pressure is gauge pressure at the cylinder port.
- Efficiency factor is a first-pass allowance, not a substitute for measuring pressure losses.
- Rod buckling, seals, mounts, hoses and valves must be checked separately.