This hydraulic calculator allows you to quickly estimate the most common hydraulic values used in cylinder and piping work. It combines four calculators into one interface and lets the user switch between Metric and Imperial units at any time.
What This Hydraulic Calculator Can Compute
This on-page tool combines four common hydraulic calculators into one interface. You can switch between
Metric and Imperial units, select the calculation type, and it will return the main
result plus supporting values (like effective area) so you can sanity-check the numbers.
1) Hydraulic Cylinder Speed Calculator (Speed from Flow)
Calculates how fast the cylinder will move when a known flow rate is supplied.
It uses the relationship v = Q / A, where A is the effective piston area.
What you can calculate:
- Cylinder linear speed (Metric: mm/s, Imperial: in/s)
- Effective area used for the calculation:
- Extend: full bore area (
A = π/4 · D²) - Retract: annulus area (
A = π/4 · (D² − d²))
- Extend: full bore area (
- Stroke time (if stroke length is entered)
- Theoretical force (if pressure is entered)
How to interpret it
- For the same flow, a larger effective area means lower speed.
- Retract speed is usually higher than extend speed because retract area is smaller.
- Stroke time helps estimate real machine cycle time for sequencing.
2) Hydraulic Cylinder Force Calculator (Force from Pressure)
Calculates theoretical cylinder force from pressure and effective area using F = P · A.
The calculator clearly distinguishes extend vs retract force.
What you can calculate
- Theoretical force (Metric: kN, Imperial: lbf)
- Effective area used in the force calculation
- Extend vs retract comparison (retract force is lower due to rod area)
How to interpret it
- Extend force is always greater than retract force at the same pressure.
- The result is ideal; real force at the load may be lower due to friction and pressure losses.
- Backpressure on the return line reduces available retract force.
3) Hydraulic Cylinder Flow Calculator (Flow Required from Speed)
Calculates the required flow rate to achieve a target cylinder speed using Q = v · A.
This is especially useful when selecting a pump or validating an existing power unit.
What you can calculate
- Required flow (Metric: L/min, Imperial: GPM)
- Effective area used in the flow calculation
- Stroke time (if stroke length is entered)
- Hydraulic power (ideal) if pressure is entered (
Power = Pressure × Flow)
How to interpret it
- Flow demand increases linearly with speed.
- For the same speed, retract typically needs less flow than extend.
- Power output helps check if your pressure + speed target is realistic for your pump/motor.
4) Hydraulic Pipe Flow Calculator (Flow, Velocity, Diameter)
Calculates the relationship between pipe inside diameter, volumetric flow, and
fluid velocity using the continuity equation Q = V · A.
What you can calculate
- Flow rate (Metric: L/min, Imperial: GPM)
- Fluid velocity (Metric: m/s, Imperial: ft/s)
- Pipe cross-sectional area (derived from inside diameter)
- Inside diameter used for the calculation (for traceability)
How to interpret it
- Larger diameter reduces velocity for the same flow.
- Higher velocity often increases heat, noise, and pressure loss in real systems.
- This calculator is volumetric only; it does not calculate pressure drop or friction loss.
Notes & Assumptions
- All results are theoretical steady-state values.
- Real systems differ due to efficiency, valve drops, hose/pipe losses, seal drag, and dynamic loads.
- For final design, validate with manufacturer data and apply appropriate safety factors.
Hydraulic Cylinder Calculation Formulas (Metric & Imperial) + Excel
Below are standard hydraulic cylinder formulas and ready-to-copy Excel formulas for both
metric and imperial units.
Metric (MPa, mm, L/min)
Inputs
- P = Pressure (MPa)
- D = Bore diameter (mm)
- d = Rod diameter (mm)
- Q = Flow (L/min)
- L = Stroke (mm)
Formulas
- Piston area: A = (π·D²)/4
- Rod-side area: Arod = (π·(D² − d²))/4
- Extend force: F = P·A
- Retract force: Fret = P·Arod
- Speed: v = Q/A
- Stroke time: t = L/v
- Hydraulic power: kW = (bar·L/min)/600Convert MPa → bar by multiplying by 10.
Excel (example cell layout)
| Cell | Meaning | Unit |
|---|---|---|
| A2 | Pressure (P) | MPa |
| A3 | Bore diameter (D) | mm |
| A4 | Rod diameter (d) | mm |
| A5 | Flow (Q) | L/min |
| A6 | Stroke (L) | mm |
Excel formulas (copy/paste)
B2 (Piston area, m^2) =PI()*(A3/1000)^2/4
B3 (Rod-side area, m^2) =PI()*((A3/1000)^2-(A4/1000)^2)/4
B4 (Extend force, kN) =A2*B2*1000
B5 (Retract force, kN) =A2*B3*1000
B6 (Extend speed, mm/s) =(A5*16.67)/(B2*10000)
B7 (Retract speed, mm/s) =(A5*16.67)/(B3*10000)
B8 (Extend time, s) =A6/B6
B9 (Retract time, s) =A6/B7
B10 (Power, kW) =(A2*10*A5)/600
Notes: Using MPa and m² gives N directly; the kN shortcut above is MPa × m² × 1000.
Speed formula uses a common shop conversion to mm/s.
Imperial (psi, inches, GPM)
Inputs
- P = Pressure (psi)
- D = Bore diameter (in)
- d = Rod diameter (in)
- Q = Flow (GPM)
- L = Stroke (in)
Formulas
- Piston area: A = (π·D²)/4
- Rod-side area: Arod = (π·(D² − d²))/4
- Extend force: F (lbf) = P (psi) · A (in²)
- Retract force: Fret (lbf) = P · Arod
- Speed: v = Q/ACommon shortcut: v (in/s) = (GPM · 231) / A (in²)
- Stroke time: t = L/v
- Hydraulic power: HP = (psi · GPM) / 1714
Excel (example cell layout)
| Cell | Meaning | Unit |
|---|---|---|
| A2 | Pressure (P) | psi |
| A3 | Bore diameter (D) | in |
| A4 | Rod diameter (d) | in |
| A5 | Flow (Q) | GPM |
| A6 | Stroke (L) | in |
Excel formulas (copy/paste)
B2 (Piston area, in^2) =PI()*A3^2/4
B3 (Rod-side area, in^2) =PI()*(A3^2-A4^2)/4
B4 (Extend force, lbf) =A2*B2
B5 (Retract force, lbf) =A2*B3
B6 (Extend speed, in/s) =(A5*231)/B2
B7 (Retract speed, in/s) =(A5*231)/B3
B8 (Extend time, s) =A6/B6
B9 (Retract time, s) =A6/B7
B10 (Power, HP) =(A2*A5)/1714
Notes: Force in lbf is psi × in². The speed shortcut uses 231 in³ per gallon.
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