Hydraulic press calculator (Pascal's law)
Pressure in a confined fluid spreads equally, so force is multiplied by the ratio of the piston areas. Enter the force and both diameters.
Loading the tool…
Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter force on the small piston, small piston diameter and large piston diameter.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Pressure p = F₁ ÷ A₁ with A = π d² ÷ 4. Output force F₂ = p × A₂ = F₁ × (d₂ ÷ d₁)².
Example
Inputs: Force on the small piston = 100 N, Small piston diameter = 20 mm, Large piston diameter = 100 mm. Result: Force on the large piston: 2,500 N; Fluid pressure: 3.1831 bar; Force multiplication: 25.
Limits and caveats
- Assumes an incompressible fluid and ignores seal friction.
- Does not include any height difference between the pistons.
Questions about this tool
Does a hydraulic press break energy conservation?
No. The small piston moves further by the same factor the force grows, so the work stays equal.
How do I convert the result to tonnes?
Divide the force in newtons by 9806.65 to get tonne-force.
How much is one bar?
1 bar equals 100000 Pa, which is 0.1 MPa.