Helpful tips

How Do You Calculate Hydraulic Pressure?

A hydraulic cylinder exerts gigantic force. So, the fluids act this way under the enormous pressure of these cylinders. And with quite a few formulas in geometry, you can even use the Hydraulic Pull Cylinder. You will learn and know such cylinder’s force or pressure in tons or pounds easily.

The pound forces fluid pressure’s product in “psi.” Multiply it with the piston’s cross-sectional area. Then, to get the exact range of the hydraulic cylinder tonnage, you have to divide the final pound force measure by 2000.

Basic information on hydraulic pumps:

Hydraulic pumps or cylinders are used to produce the fluid into a system. The pressure that occurs in the system occurs when the fluid’s flow shows some resistance.

This is according to Pascal’s Law. According to it, fluids transmit in various available directions at the same pressure; that’s when force is applied to any given point in the chosen system, confined.

So, the hydraulic pull cylinder will move at its set rate depending upon the load’s weight in the system. Cylinders with heavy weight lift later than those with lighter loads.

Where do we find hydraulic machines?

In elevators, cranes, and brakes.

These machines are best to lift numerous loads together or to drill precision holes with equalized efforts.

Why and when we need hydraulic pressure?

To lift different hydraulic cylinders with different loads at the same time, we need pressure control valves.

That is when any engineer working on the cylinders needs to count the hydraulic cylinder pressure.

Basic ways to calculate this pressure:

There is one common formula for calculating pressure.


In the above equation, F denotes the Force, P is the Pressure needed, A is the defined surface area. We can reverse the equation to find P. The equation will then be P=F/A.

Tips while calculating the hydraulic cylinder pressure:

Pressure when you calculate in pounds/sq. feet is the Force in pounds/unit area in sq. inches.

You must know Pascal’s Law and its assumptions properly before calculating the pressure manually. Even if you are driving its theorem or formula, the assumptions help a lot.

For instance, while calculating the pressure, assume that:

  • Hydraulic fluid doesn’t compress. Yet, it transmits the power instantly.
  • As a small force on a smaller area would release a directly proportional large force on a larger surface, the limiting factor in this equation is the area.

In other words, the area can manipulate or adjust the pressure to be used from the hydraulic cylinders.

Deterministically we can say that to determine hydraulic pull cylinder pressure; you need to know two factors. These are surface area and the force to be applied through the piston.

Warnings to pay immediate attention to:

  • The value of the hydraulic pressure must equate with the pressure to be put in the small piston with the small force.

It is the same case when the pressure is decided for a large piston and its large force.

  • When there is any mismatch in the details of the Force, Surface Area, and Pressure, you need to recalculate the measurements.

Using the wrong force in the wrong area can result in disastrous pressure from the hydraulic cylinders. This can ruin the projects you are working on at the moment.

  • So, you must know the right parameters—most of them discussed in this blog already.
  • As the surface area and force are used to calculate pressure, they are also useful in calculating the certain pressure for a moving piston or its part.

SI units of Pressure and Applied Force

One Pascal (going by Pascal’s Law) is Pressure’s SI unit. It has a value of 0.000145 pounder/sq. inch roughly.

Whereas, Newton is Force’s SI unit. One Newton is about 0.225 pounds.


1 Pa = 1 N/m2

Scientists define one Pascal to have one Newton value per square meter.

While measuring parts of the machines before calculating the pressure, engineers often measure the chosen area in square millimeters. They let go of the square meter concept.

Following this convention, the equation would then be:

1 MPa = 0.001 kN/mm2

Here, MPa is the “mega” Pascal, and kN is the “Kilos” Newton.

Now calculating the Pressure formula in simpler terms, that was, P=F/A, we get:

1 kN/mm2 = 1,000 MPa.

This formula is helpful when you know the force is used to compress a liquid into the hydraulic cylinder.