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Hydraulic Cylinder Force Calculator

Enter the bore, rod and pressure and get the cylinder's push and pull force in pounds, tons and kilonewtons, or the pressure needed for a force.

Auto & MechanicalWorldwideSource: Force = pressure × area (OpenStax College Physics 2e)Free, no sign-up

The result updates as you type.

Theoretical force

Push 17,671 lbf · pull 13,254 lbf

8.84 / 6.63 short tons · 78.6 / 59 kN · 8.02 / 6.01 tonnes-force

Piston area (push)7.069 in² (4,560 mm²)
Annulus area (pull, piston minus rod)5.301 in² (3,420 mm²)

What this page cannot tell you

Real output after friction, seal drag and pressure losses, which is lower; whether the cylinder, rod, pins or mounting are rated for this force; or buckling of a long rod in compression. Never exceed the cylinder's rated pressure.

Method: force = pressure × area (pressure is force per unit area — OpenStax College Physics 2e §11.3); push uses the bore area, pull the bore minus the rod. 1 bar = 14.5038 psi; 1 lbf = 4.44822 N. Retrieved 2026-10-17.

Pressure needed for a push force

Uses the bore and number of cylinders above.

How to calculate hydraulic cylinder force

  1. Enter the bore. Inside diameter of the barrel (piston diameter).
  2. Enter the rod. Rod diameter, for the pull (retract) force.
  3. Enter the pressure. Working pressure in psi or bar.
  4. Read push and pull. In lbf, short tons, kN and tonnes-force.

10 situations where a cylinder force calculator helps

Log splitters

Tons of splitting force from bore and pump pressure.

Choosing a cylinder

Find the bore that gives the force you need at your pressure.

Retract vs extend

Pull force is lower because the rod takes up piston area.

Tractor loader and 3-point work

Estimate lift cylinder force.

Press builds

Shop presses rated in tons.

Dump trailers

Force available to lift a bed.

Metric cylinders

Enter mm and bar; get kN and tonnes.

Two cylinders in parallel

Multiply force by the number working together.

Pressure needed

Work backwards from a force to the pressure.

Teaching hydraulics

A worked example of force = pressure × area.

How the force is worked out

Pressure is force per unit area (OpenStax College Physics 2e §11.3), so force = pressure × area. Extending, the fluid pushes on the whole piston: area = π × bore² ÷ 4. Retracting, the rod takes up part of the piston, leaving the annulus: area = π × (bore² − rod²) ÷ 4. With psi and square inches the result is pounds-force.

Conversions: 1 bar = 14.5038 psi; 1 lbf = 4.44822 N; a short ton-force is 2,000 lbf and a tonne-force 9,806.65 N.

Limits: this is theoretical force. Seal friction, pressure losses and the relief valve setting reduce real output, and a cylinder, rod, pins and mountings each have their own ratings. A long rod under compression can buckle well below this force. Never exceed the cylinder's rated pressure. Everything runs in your browser.

Frequently asked questions

How do I calculate hydraulic cylinder force?

Force (lbf) = pressure (psi) × piston area (in²). A 3 in bore at 2,500 psi pushes about 17,671 lbf (8.8 tons).

Why is the pull force lower?

On retract the rod occupies part of the piston area, so less area sees pressure.

How many tons is my log splitter?

Bore area × pump pressure ÷ 2,000. A 4 in bore at 3,000 psi is about 18.8 tons.

How do I convert bar to psi?

Multiply by 14.5038.

What pressure do I need for a given force?

Force ÷ piston area; use the second calculator on the page.

Is the real force the same?

It's lower — friction and losses take some, and relief valves limit pressure.

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