Hydraulic Cylinder Force Calculator
By Santaji GadepatilinUpdated October 27, 2026
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Type in any field to change it. Press × on a value to calculate that field instead.
Push force (extend) (kN) vs Working pressure (bar) — other inputs held at your current values.
How to use this calculator
Enter the working pressure, bore and rod diameter. You get the extend (push) and retract (pull) forces. To find the pressure needed for a load, press × on Working pressure and type the force.
The formulas
Fpush = P × π d² ÷ 4
Fpull = P × π (d² − r²) ÷ 4
Worked example
A 50 mm bore, 28 mm rod cylinder at 160 bar:
- Push = 16,000,000 Pa × 0.001963 m² = 31.4 kN (about 3.2 tonnes)
- Pull = 16,000,000 Pa × 0.001348 m² = 21.6 kN
Quick sizing tips
- Add a safety margin of 20–30% over the calculated load.
- Check the rod for buckling on long strokes — slender rods can fail before the force limit is reached.
- Cylinder speed depends on pump flow: speed = flow ÷ effective area.
Frequently asked questions
Why is the pull force lower than the push force?
When retracting, the rod takes up part of the piston area, so oil pushes on a smaller annular area.
How do I convert kN to tonnes?
Choose "tonne-force" as the force unit. 1 tonne-force ≈ 9.81 kN.
Should I use the full system pressure?
Use the pressure available at the cylinder. Losses in hoses and valves, plus friction in the seals, reduce the real force by a few percent.