Pneumatic Cylinder Force Calculator #
Calculate push/pull force, minimum bore size, free-air consumption per cycle, and piston speed for single-acting and double-acting pneumatic cylinders. Supports metric and imperial units with a built-in bore reference series; verify the actual cylinder family and size in the OEM catalog.
Input Parameters
Advanced calculator
Rod size, load factor, available flow, cycle rate, and cylinder action refine force and air use.
About This Calculator
This pneumatic cylinder sizing calculator supports both quick bore estimates and advanced configuration with metric/imperial units, single/double acting modes, and reverse force-to-bore calculation. It uses Pascal's principle to determine the theoretical and actual force output of a pneumatic cylinder. It accounts for rod diameter reduction on the retract stroke, applies a user-selectable load factor for real-world safety margin, and estimates free air delivery (FAD) consumption for compressor sizing. Browse all pneumatic calculators for related tools including air compressor sizing and compressed air pipe sizing.
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After cylinder force and air consumption, size the compressor for total CFM demand and the piping for pressure drop.
Standard Pneumatic Cylinder Bore Sizes #
The calculator selects the next size from its built-in metric or imperial reference series without rounding down. The series spans sizes used across multiple cylinder families; it is not proof that a size, mounting, rod, pressure rating or profile is available under a particular standard. Verify the exact OEM catalog.
| Standard | Bore Sizes | Typical Application |
|---|---|---|
| ISO 6432 (metric micro) | 8, 10, 12, 16, 20, 25 mm | Small automation, clamping, light assembly |
| ISO 15552 (metric industrial) | 32, 40, 50, 63, 80, 100, 125, 160, 200, 250, 320 mm | General industrial automation, packaging, material handling |
| NFPA (imperial) | 9/16, 5/8, 3/4, 1 1/16, 1 1/4, 1 1/2, 2, 2 1/2, 3, 4, 5, 6, 8 inch | North American machinery, mobile equipment |
| Compact / Short Stroke | 12, 16, 20, 25, 32, 40, 50, 63, 80, 100 mm | Space-constrained installations, ejection, pressing |
Source: ISO 6432:2015, ISO 15552:2018, NFPA T3.6.1 R1-2014. Always verify exact dimensions and mounting patterns with the cylinder manufacturer's datasheet.
Formulas and Calculation Method #
Force Calculation
Pneumatic cylinder force is derived from Pascal's principle: pressure acts uniformly on the piston area. The theoretical force depends on whether the cylinder is extending or retracting:
Push (extend): F_push = P × π × D² / 4
Pull (retract): F_pull = P × π × (D² - d²) / 4
Effective force: F_eff = F_theoretical × load_factor
Where: D = bore diameter, d = rod diameter, P = gauge supply pressure (absolute for FAD calculations). The rod diameter reduces the effective piston area on the retract side, so pull force is always less than push force for the same bore and pressure.
Bore Sizing (Reverse Calculation)
When the required force is known, solve for the minimum bore diameter:
D_min = sqrt(4 × F_required / (π × P × load_factor))
After calculating D_min, select the next larger standard bore size from the reference table above. This ensures the cylinder can produce the required force even at the minimum available system pressure, accounting for pressure drops in filters, regulators, valves, and tubing.
Air Consumption
Air consumption is calculated as the total swept volume per cycle, converted to free air delivery (FAD) at atmospheric pressure:
Extend volume: V_ext = π/4 × D² × S
Retract volume: V_ret = π/4 × (D² - d²) × S (double-acting only)
Per cycle (FAD): V_cycle = (V_ext + V_ret) × (P_gauge + P_atm) / P_atm
Continuous consumption: Q = V_cycle × cycles_per_minute
Single-acting cylinders consume air only on the power stroke (extend), with the return stroke driven by spring or external load. The pressure ratio converts compressed volume to equivalent free air, which is what the compressor must deliver.
Piston Speed
Given a known air flow rate, the average piston speed is:
v = Q / A = 4Q / (π × D²) (convert Q to consistent volume/time units)
Typical pneumatic cylinder speeds range from 50-500 mm/s. Speeds above 500 mm/s require cushioning at stroke end to prevent impact damage. The actual speed is limited by valve flow capacity (Cv), port size, and exhaust muffler restriction, not just supply flow.
Force Reference Chart (6 bar / 87 PSI) #
Quick reference for theoretical push force at common supply pressure of 6 bar (87 PSI), with 65% load factor applied for effective working force. Rod diameter assumed as 50% of bore for retract force.
| Bore (mm) | Push (N) | Pull (N) | Effective Push (N) | Air/Cycle (L FAD) | Typical Application |
|---|---|---|---|---|---|
| 16 | 121 | 91 | 79 | 0.18 | Small clamping, sorting gates |
| 25 | 295 | 221 | 192 | 0.44 | Light assembly, label applicators |
| 32 | 483 | 362 | 314 | 0.72 | General automation, pushers |
| 40 | 754 | 566 | 490 | 1.13 | Packaging, conveyors, clamping |
| 50 | 1,178 | 884 | 766 | 1.77 | Material handling, lifting assists |
| 63 | 1,870 | 1,403 | 1,216 | 2.81 | Heavy clamping, pressing, lifting |
| 80 | 3,016 | 2,262 | 1,960 | 4.52 | Heavy pressing, die casting, stamping |
| 100 | 4,712 | 3,534 | 3,063 | 7.07 | Very heavy loads, industrial presses |
Assumptions: 6 bar gauge supply, rod diameter = 50% of bore, 100 mm stroke, 65% load factor. Air/cycle values are FAD (free air delivery). Actual values vary by cylinder manufacturer and system configuration.
Frequently Asked Questions #
What is the formula for pneumatic cylinder force?
The theoretical push force is F = P × π × D² / 4, and double-acting retract force is F = P × π × (D² - d²) / 4. The page multiplies push force by the load factor you explicitly select; choose that factor from the application's motion, friction, minimum inlet pressure and OEM evidence.
How do I choose the right bore size for my cylinder?
Calculate the minimum bore using D = sqrt(4F / (π × P × load factor)), then select the next non-smaller size from a relevant manufacturer series. This calculator's reference series is not an OEM availability or standards-conformance claim.
What is the difference between single-acting and double-acting cylinders?
Single-acting cylinders use air pressure to extend and a spring or external load to retract. They consume air only on the extend stroke and are simpler but limited in stroke length. Double-acting cylinders use air pressure for both extend and retract, providing controlled force in both directions and are the most common choice for industrial automation.
How much air does a pneumatic cylinder consume?
Air consumption per cycle equals the total swept volume: extend volume = π/4 × D² × S, retract volume = π/4 × (D²-d²) × S (double-acting only). Convert to free air delivery (FAD) by multiplying by the absolute pressure ratio (P_gauge + 1.013) / 1.013. Multiply by cycles per minute to get CFM or L/min demand on the compressor.
What load factor should I use for cylinder sizing?
There is no universal value. Select it from the required acceleration, friction and side load, minimum pressure at the cylinder, duty cycle and OEM guidance, then document the assumption. Lower entered factors increase the calculated minimum bore.
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