How do I calculate pneumatic cylinder force?

Pneumatic cylinder extend force is F = P × A, where P is the supply pressure and A is the full bore area (π/4 × D²). Retract force uses the annular area: A = π/4 × (D² − d²), where d is the rod diameter.

What is the difference between extend and retract force?

Extend force uses the full piston bore area, so it is always higher. Retract force uses the annular area (bore area minus rod area), giving a lower force output.

How do I calculate pneumatic cylinder speed?

Piston speed v = Q / A, where Q is the volume flow rate and A is the effective piston area. For extension, A is the full bore area; for retraction, A is the annular area.

What bore size do I need for a given force?

Rearrange F = P × A to find A = F / P, then D = √(4A/π). Always size up to the next standard bore diameter and include a safety factor of 25–50% for friction and dynamic loads.

Does friction affect pneumatic cylinder force?

Yes. Seal friction typically reduces the theoretical force by 5–20% depending on seal type, lubrication, and speed. A common design practice is to apply a 10–15% friction loss factor.

Free Engineering Tool — #143

Pneumatic Cylinder Force & Speed Calculator

Calculate extend/retract force and piston speed for pneumatic cylinders. Enter bore, rod diameter, and supply pressure.

F = P × A v = Q / A Extend & Retract

Results

Extend Force (Push)

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Retract Force (Pull)

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Bore Area

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Annular Area

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Extend Speed

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Retract Speed

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Cylinder Extend Force

When the piston extends, pressure acts on the full bore area:

Cylinder Retract Force

When retracting, the rod occupies part of the piston, reducing effective area:

Piston Speed

Speed depends on the air flow rate and effective piston area:

P — supply pressure
D — bore diameter
d — rod diameter
Q — volume flow rate at working pressure

Standard Bore Sizes (ISO 15552)

Bore (mm)	Rod (mm)	Extend Area (cm²)
32	12	8.04
40	16	12.57
50	20	19.63
63	20	31.17
80	25	50.27
100	25	78.54
125	32	122.72
160	40	201.06
200	50	314.16

Example — 63 mm Cylinder at 6 bar

Given: Bore = 63 mm, Rod = 20 mm, Pressure = 6 bar

A_bore = π/4 × 63² = 3117 mm² = 31.17 cm²

F_extend = 6 × 10⁵ × 3117 × 10⁻⁶ = 1870 N (190.6 kgf)

A_annular = π/4 × (63² − 20²) = 2803 mm²

F_retract = 6 × 10⁵ × 2803 × 10⁻⁶ = 1682 N (171.4 kgf)

⚠️ Note: Actual force is reduced by 5–20% due to seal friction. Apply a safety factor when sizing cylinders for real applications.

Pneumatic Cylinder Force & Speed Calculator | Free Online Tool

Published by Nikolai Shelkovenko on February 15, 2026 February 15, 2026

Results

Cylinder Extend Force

Cylinder Retract Force

Piston Speed

Standard Bore Sizes (ISO 15552)