Hydraulic Cylinder Force Calculator

Push and pull force of a hydraulic cylinder from bore, rod diameter and pressure — in kN and metric tons.

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Force = Pressure × Area

Push (extend) force acts on the full piston area: F = π/4 · D² · P. Pull (retract) acts on the annulus, the piston minus the rod: F = π/4 · (D² − d²) · P — which is why every cylinder pulls weaker than it pushes. With pressure in bar and diameters in mm, 1 bar = 0.1 N/mm², so a Ø100 mm bore at 200 bar pushes π/4 · 100² · 20 ≈ 157 kN ≈ 16 metric tons.

Real-world output runs 90-95% of theoretical due to seal friction; the tool shows the theoretical value. For speed, flow rate matters instead: extend speed = flow ÷ piston area.

Frequently Asked Questions

Why is pull force always lower than push?

The rod occupies part of the piston face on the retract side, so pressure acts on a smaller ring-shaped area. A Ø100 bore with a Ø56 rod retracts with about 69% of its extend force.

What pressure should I assume?

Standard industrial hydraulics run 160-250 bar; mobile equipment 250-350 bar; hand pumps up to 700 bar. Use your relief-valve setting — the cylinder only sees what the circuit delivers.

How do I convert kN to tons?

Divide by 9.81: 157 kN ≈ 16.0 metric tons of equivalent load. The tool shows both.

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