How do I convert pressure units?

One megapascal equals 1,000,000 pascals and is the same as 10 bar, while 1 bar is roughly 14.5 psi. Enter pressure in pascals here, so 10 MPa becomes 10,000,000. Getting the units right is the most common source of error.

Is the retract force the same as the extend force?

No. On extension the full piston area is pressurised, but on retraction the rod takes up part of that area, so the effective area and the resulting force are smaller. This calculator gives the full-bore extend force.

Does this account for friction and losses?

No, it gives the theoretical force from pressure and area only. Real cylinders lose some force to seal friction and pressure drop, so the usable output is a little lower. Allow a sensible margin when sizing a cylinder.

Hydraulic Force Calculator

The hydraulic force calculator works out how much pushing force a hydraulic cylinder can deliver from its operating pressure and bore size. It applies the core relationship that force equals pressure multiplied by area, where the piston area is pi divided by four times the bore diameter squared. You enter two inputs: the operating pressure in pascals and the cylinder bore diameter in metres. The calculator returns the output force in both kilonewtons and newtons, along with the piston area in square millimetres so you can sanity-check the geometry. Hydraulic system designers, machine builders, mobile-plant technicians and students use it to size cylinders for presses, lifts, clamps, log splitters and earthmoving gear, and to confirm a ram will produce enough force for the job. Because force scales with the square of the bore, a small increase in diameter gives a large gain in force, which is why bore choice dominates cylinder selection. A few tips keep your numbers realistic. First, this calculation gives the force on the full piston during extension; on the retract stroke the rod reduces the effective area, so the pulling force is lower. Second, use the system working pressure, not the relief-valve setting, and leave a margin for pressure drop and friction losses. Third, watch your units: one megapascal equals 1,000,000 pascals and equals 10 bar, so converting carefully avoids errors of a thousandfold. Always confirm the cylinder, hoses and mounts are rated for the pressure before applying real loads.

Operating pressure (Pa)

Bore diameter (m)

19.63 kN

Output force

Force in newtons19,635 N

Piston area1963.5 mm2

F = P x A, where A = (pi/4) x d^2. Estimate only, not engineering design advice.

How it works

The piston area equals pi divided by four times the bore diameter squared. The output force is that area multiplied by the operating pressure. Because the area depends on diameter squared, force rises quickly as the bore gets larger.

Worked example

With a bore of 0.05 m, the area is pi/4 times 0.05 squared, which is 0.0019635 m^2 or 1963.5 mm2. At a pressure of 10,000,000 Pa, the force is 0.0019635 times 10,000,000, giving 19,635 N or 19.63 kN.

Related calculators

Bolt Torque Calculator: bolt tightening torque.
Euler Column Buckling Calculator: critical buckling load.
Hazen-Williams Pipe Flow Calculator: pipe head loss.

If you've found a bug, or would like to contact us, or learn more about James Graham and Calculate.co.nz.

Calculate.co.nz is partnered with Interest.co.nz for New Zealand's highest quality calculators and financial analysis.

All calculators and tools are provided for educational and indicative purposes only and do not constitute financial advice.

Calculate.co.nz is proudly part of the Realtor.co.nz group, New Zealand's leading property transaction literacy platform, helping Kiwis understand the home buying and selling process from start to finish. Whether you're a first home buyer navigating your first property purchase, an investor evaluating your next acquisition, or a homeowner planning to sell, Realtor.co.nz provides clear, independent, and trustworthy guidance on every step of the New Zealand property transaction journey.

Calculate.co.nz is also partnered with Health Based Building and Premium Homes to promote informed choices that lead to better long-term outcomes for Kiwi households.

Calculate.co.nz is hosted in Auckland via SiteHost new Zealand.

All content on this website, including calculators, tools, source code, and design, is protected under the Copyright Act 1994 (New Zealand). No part of this site may be reproduced, copied, distributed, stored, or used in any form without prior written permission from the owner.