Linear Actuator Force Calculator

Work out linear actuator force instantly with clear inputs, formula shown and shareable results.

About Linear Actuator Force Calculator

Cylinder force is pressure times effective area. On extension the full bore area acts, but on retraction the rod area is subtracted, so a 40 mm bore with a 16 mm rod retracts with only about 84% of its extend force — the asymmetry that catches out clamping and pressing applications.

Formula

Cylinder force

extend = P x pi D^2/4; retract = P x pi (D^2 - d^2)/4, both x efficiency

Worked example

With the default values below, Linear Actuator Force Calculator returns Extend force of 678.58. Change any input above and every figure here is recalculated in your browser.

Inputs used

Supply pressure: 6 bar
Cylinder bore: 40 mm
Rod diameter: 16 mm
Mechanical efficiency: 90 %

Results

Extend force: 678.58 N
Retract force: 570.01 N
Bore area: 1,256.64 mm²
Annulus area: 1,055.58 mm²

Step by step

1Values used
2Cylinder force
3Extend force= 678.58 N
4Retract force= 570.01 N
5Bore area= 1,256.64 mm²
6Annulus area= 1,055.58 mm²

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why is retract force lower?

The rod occupies part of the piston face on the annulus side, so less area is available for the pressure to act on.

What efficiency should I assume?

85-95% for a well-lubricated pneumatic cylinder. Seal friction and side loading account for the loss, and it worsens at low pressure.