Question 1

How do I calculate hydraulic cylinder force?

Accepted Answer

Force equals pressure times the piston area the fluid pushes on. Extending, the fluid acts on the full bore area A = π/4 × D², so F = P × A. With pressure in MPa and area in mm² the result is in newtons, because 1 MPa = 1 N/mm². For example 16 MPa on a 63 mm bore gives 16 × 3117 ≈ 49.9 kN.

Question 2

Why is the pull (retract) force smaller than the push force?

Accepted Answer

On the rod side the piston rod occupies part of the piston face, so the fluid only acts on the annular area A_ann = π/4 × (D² − d²). Since that area is smaller than the full bore, the retract force F = P × A_ann is always less than the extend force at the same pressure.

Question 3

How do I work out the rod speed from the pump flow?

Accepted Answer

Speed is flow divided by the area being filled. Convert flow Q from L/min to mm³/s (multiply by 1,000,000 and divide by 60), then v_extend = Q / A_bore and v_retract = Q / A_annulus. The retract stroke is faster because the annular area is smaller.

Question 4

How do I convert bar to MPa for cylinder force?

Accepted Answer

Divide bar by 10: 1 bar = 0.1 MPa, so 160 bar = 16 MPa. Working in MPa with millimetre areas keeps the force directly in newtons, which you can divide by 1000 for kilonewtons or by 9.81 for kilograms-force.

Question 5

Is the calculated force the real output force?

Accepted Answer

No. It is the ideal theoretical force. Real cylinders lose some force to seal friction, and the retract stroke also fights any back-pressure on the rod side and the cylinder's volumetric and mechanical efficiency. Buckling of a long rod is a separate check. Always apply a design safety factor.

Hydraulic CylinderForce Calculator

Hydraulic Cylinder
Force Calculator