Hydraulic Force Calculator

How Cylinder Force Is Calculated

A hydraulic cylinder converts fluid pressure into a linear pushing or pulling force. The force available depends on two things: the system pressure in bar and the effective piston area in mm². On extension, the full bore area is pressurized, giving the maximum force; on retraction, the rod takes up part of that area, so the effective area is the annulus between bore and rod and the force is lower.

The tool uses the standard formula F = P × A, with pressure converted to pascals and the area calculated from the diameters: Ff = P × π × D² / 4 for extension and Fb = P × π × (D² − Dr²) / 4 for retraction. Results are given in newtons with an approximate kgf equivalent, matching the way force figures are quoted in European ISO drawings and catalogues.

Recommended Workflow

• Set pressure — pick a standard system pressure in bar (ISO 3322 series), for example 160 bar.
• Choose the cylinder — select a bore/rod combination from the standard ISO 3320 sets, such as Ø63/36.
• Read both forces — extension force uses the full bore area, retraction force uses the annular area.
• Copy values — click any underlined result to copy it for your drawing or report.

Check the Buckling Situation

Keep in mind that the geometry formula gives the theoretical force, not the usable one. For long-stroke cylinders, check the rod against Euler buckling; for heavy loads, verify the cushioning and the machine's mechanical guides. The Calculation Details box shows every step with units converted, so you can audit the math before the figures go into a design review.