In a hydraulic cylinder, force scales with the piston diameter squared, not the diameter itself.
Force = pressure × area, and area = π(d/2)² — a 2:1 diameter ratio between two pistons gives a 4:1 force ratio at the same pressure, exactly how a hydraulic jack multiplies a small hand force into tonnes.
On the extend stroke. Retracting, the rod area is subtracted from the piston, so a cylinder with a 2:1 rod pulls only about half as hard as it pushes at the same pressure — which is why a press returns faster than it advances, and why pulling loads need the bore sized on the annulus.
Estimate with the rule, then check it against the calculator that models it properly.
Open Hydraulic Force Calculator →In a hydraulic cylinder, force scales with the piston diameter squared, not the diameter itself. Force = pressure × area, and area = π(d/2)² — a 2:1 diameter ratio between two pistons gives a 4:1 force ratio at the same pressure, exactly how a hydraulic jack multiplies a small hand force into tonnes.