Hydraulic Cylinder Speed Calculator
Enter flow in L/min and cylinder dimensions in mm. Select extension or retraction and enter 1–20 bores to compare both strokes.
A QUICK WALKTHROUGH
How to use this tool
- Enter finite flow in L/min (zero or greater) and bore diameter in mm (greater than zero).
- Select extension or retraction and enter a finite rod diameter in mm (zero or greater). Retraction requires the rod to be smaller than the bore.
- Enter 1–20 bore diameters on separate lines to compare both strokes using the same flow and rod. Review the scope before exporting the report.
Formulas and units
Piston area: Aₑ = πd²/4. Rod-side annular area: Aᵣ = π(d² − r²)/4 = π(d − r)(d + r)/4. Ideal speed: v (mm/s) = Q (L/min) × 1,000,000 ÷ [60 × A (mm²)]; v (m/s) = v (mm/s) ÷ 1,000. Bore d and rod r are entered in mm.
Scope and assumptions
This is ideal kinematic arithmetic for the entered flow and geometry. It excludes leakage, fluid and hose compressibility, pressure, load, friction, acceleration, efficiency, duty cycle, ratings, and safety or actuator selection. It is not a sizing or operating instruction.
Reference
Parker, Hydraulic Cylinder Catalog (manufacturer reference for cylinder terminology and geometry): https://www.parker.com/content/dam/Parker-com/Literature/Accumulator---Cooler-Division---Americas/Catalogs---Bulletins/GAD-HY10-1630-5-2012/ACD_CoolerCatalog_HY10_1700.pdf. The catalog is not used to infer a rating for your equipment.
Local processing
Inputs and the report stay in this browser. No data is uploaded.
GOOD TO KNOW
Common questions
Why are extension and retraction speeds different?
Retraction uses the annular area after subtracting the rod cross-section. For the same flow, its smaller effective area gives a higher ideal speed.
Can the rod equal the bore?
No for retraction. The rod must be nonnegative and strictly smaller than the bore; an invalid comparison row remains visible with an error.
Does this predict installed cylinder performance?
No. It is ideal arithmetic and excludes leakage, compressibility, pressure, load, friction, ratings, and safety or equipment selection.