Force calculator
Push & pull
force.
Enter bore, rod, and pressure. Get extend and retract force in pounds and tons — the same math the configurator runs, isolated so you can check one number fast.
Inputs
- Push force
- —
- Pull force
- —
- Bore area
- —
- in²
- Annulus area
- —
- in² (rod side)
Carries your bore, rod, and pressure into the live configurator — drawing, buckling, speed, and RFQ.
This calculator returns the theoretical push and pull force of a hydraulic cylinder from three inputs — bore, rod diameter, and system pressure — using F = P × A. Use it the moment you need to know whether a given bore and pressure can move your load, before you commit to a build or a pump. Push force uses the full bore area; pull force uses the annulus (bore minus rod), so the two numbers are never equal.
What the numbers mean
Hydraulic force is pressure acting over an area. On the extend stroke, pressurized oil pushes on the entire piston face, so the working area is the full bore circle, (π/4)·D². On the retract stroke the rod occupies part of the piston, so oil only acts on the ring left over — the annulus, (π/4)·(D² − d²). Same pressure, smaller area, less force. That asymmetry is fundamental to every single-rod cylinder and it drives how you size a machine: if the load is heaviest on the way out, size to push; if it fights you on the way back, size to pull.
A worked example: a 4-inch bore with a 2-inch rod at 3,000 PSI. Bore area is 12.57 in², so push force is 12.57 × 3,000 ≈ 37,700 lbf, about 18.8 tons. The annulus area is 9.42 in², so pull force is 9.42 × 3,000 ≈ 28,300 lbf, about 14.1 tons. Bump pressure to 5,000 PSI and both scale linearly — push climbs to roughly 62,800 lbf. That linearity is why raising pressure is often cheaper than growing the bore, up to the limits of the tube, seals, and rod.
Where the theoretical number stops
This tool gives you the ideal force. The cylinder on your machine will deliver a few percent less. Seal friction, breakaway stiction on a cold morning, and back-pressure on the return line all subtract from the net working force. None of that is guesswork we can do for you from a web form — it depends on your fluid, temperature, and circuit. The right move is to size with a sensible margin here, then let a real engineer confirm the working number against your duty cycle. Bore and pressure also feed rod buckling, seal speed, and mount loads, so a force that looks fine in isolation can still push a rod past its limit.
Next steps
- Check the rod against buckling with our rod buckling calculator.
- Confirm the speed your flow gives with the cylinder speed calculator.
- Hit Configure this cylinder to carry these values into the full build and get a firm quote.
Force calculator FAQ
How do you calculate the push force of a hydraulic cylinder?
Push (extend) force equals system pressure times the full bore area: F = P × (π/4 × D²), where D is the bore diameter. A 4-inch bore at 3,000 PSI develops about 37,700 lbf — roughly 18.8 US tons. The rod is not in the extend equation because oil pushes on the entire piston face.
Why is the pull force lower than the push force?
On retract, oil acts on the annulus — the piston face minus the cross-section the rod takes up. The effective area is (π/4)(D² − d²), where d is the rod diameter, so the pull force is always less than the push force for the same pressure. A bigger rod means more push/pull imbalance and a faster retract stroke.
Should I size to push force or pull force?
Size to whichever direction does the work. Most cylinders push to do the job (lift, clamp, dump), so extend force usually governs. If your load pulls the rod back in — a tie-down or a closing motion — pull force governs and you may need to raise pressure or bore to hit the number.
Does this account for friction and efficiency losses?
No. This is theoretical force from pressure and area. Real cylinders lose a few percent to seal friction, and back-pressure on the return line eats into net force. Size with margin, and let our engineers confirm the working number against your duty cycle before you build.