Fareed Mohmed · Engineering
Pneumatic Cylinder Force Calculator
Bore · Pressure · Force
Pick a standard cylinder bore on the left and see its matched rod size and piston area. Set the supply pressure on the right and see extension and retraction force update live.
Bore & Force Calculator
Bore-to-rod pairings follow the common ISO 6431 / VDMA 24562 sizing used across standard pneumatic cylinder ranges. Force figures assume a double-acting cylinder; actual output depends on the specific cylinder's seal friction and the real line pressure at the cylinder port, not just the regulator setting.
Cylinder Bore
Force Output
Standard Bore Sizes Reference
| Bore | Rod | Full-Bore Area (mm²) | Annulus Area (mm²) |
|---|---|---|---|
| Ø8 mm | Ø4 mm | 50.3 | 37.7 |
| Ø10 mm | Ø4 mm | 78.5 | 66.0 |
| Ø12 mm | Ø6 mm | 113.1 | 84.8 |
| Ø16 mm | Ø6 mm | 201.1 | 172.8 |
| Ø20 mm | Ø8 mm | 314.2 | 263.9 |
| Ø25 mm | Ø10 mm | 490.9 | 412.3 |
| Ø32 mm | Ø12 mm | 804.2 | 691.2 |
| Ø40 mm | Ø16 mm | 1,256.6 | 1,055.6 |
| Ø50 mm | Ø20 mm | 1,963.5 | 1,649.3 |
| Ø63 mm | Ø20 mm | 3,117.2 | 2,803.1 |
| Ø80 mm | Ø25 mm | 5,026.5 | 4,535.7 |
| Ø100 mm | Ø25 mm | 7,854.0 | 7,363.1 |
| Ø125 mm | Ø32 mm | 12,271.8 | 11,467.6 |
| Ø160 mm | Ø40 mm | 20,106.2 | 18,849.6 |
| Ø200 mm | Ø40 mm | 31,415.9 | 30,159.3 |
| Ø250 mm | Ø45 mm | 49,087.4 | 47,497.0 |
| Ø320 mm | Ø50 mm | 80,424.8 | 78,461.3 |
Explanatory Notes
Where the force formula comes from
Force equals pressure times area. Since 1 bar = 0.1 N/mm², the shortcut used here is Force (N) = Pressure (bar) × Area (mm²) × 0.1 — no unit conversion gymnastics needed once area is in mm².
Why retraction is always weaker than extension
On extension, full pressure pushes against the entire piston face. On retraction, the piston rod occupies part of that face on the rod side, so the same pressure acts on a smaller annular area — the piston rod's own cross-section is "lost" to the force calculation. A thicker rod (chosen for buckling resistance on a long stroke) costs you some retraction force in exchange.
Theoretical vs. typical operating force
The 100% figure is the textbook pressure×area number. Real cylinders lose some of that to seal friction, and at low pressure, static friction ("stiction") can be a larger fraction of the available force — a cylinder sized right at its theoretical limit may not break away reliably at low pressure. The ~90% "typical operating" figure is a common rule-of-thumb allowance, not a guarantee; check the manufacturer's datasheet for a load right at the edge of what the cylinder can deliver.
Leave a safety margin
Don't size a cylinder to just barely move its load at line pressure. Line pressure sags under flow, seals wear over the cylinder's life, and friction increases in cold conditions — sizing for meaningfully more force than the bare minimum keeps the actuator reliable in service, not just on the day it's commissioned.
Related tools
For sizing the fasteners that mount a cylinder's clevis or flange, see Bolt Grades — Axial, Shear & Torque.