Pneumatic Cylinder Sizing Calculator

What this tool does

A cylinder's theoretical force is pressure times piston area: at 6 bar each square centimetre gives 60 N. You can never count on all of it, because the seals take their share in friction and the cylinder needs force left over to accelerate the load. That is why the bore is chosen with a load ratio; a common rule of thumb is about 70 % for slow movements and 50 % or less when the load must move quickly. Use the pressure at the cylinder, not at the compressor: after the valve and the hoses it is often half a bar to a bar lower. On the way back the rod takes up part of the piston area, so the pulling force is always smaller.

Formula

D = √(4 F ÷ (π × p × load ratio)) · F_out = p × π D² ÷ 4 · F_back = p × π (D² − d²) ÷ 4

Variables

Worked example

Limitations

• Coverage and consumption figures vary between products. Take the values from the manufacturer's datasheet for the product you are actually using.
• The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.