Hydraulic Cylinder Speed Calculator
Find cylinder speeds, travel times or the required flow.
Results
Extension speed
- Retraction speed
- 132.63 mm/s7,957.75 mm/min5.22 in/s
- Extension travel time
- 5.03 s
- Retraction travel time
- 3.77 s
- Piston area
- 5,026.55 mm²
- Annular area
- 3,769.91 mm²
This is a theoretical single-rod cylinder model. Leakage, fluid compressibility, valve restrictions, acceleration and end cushioning are not included. A nonzero stroke cannot complete at zero flow; its travel time is shown as unavailable.
Formula · How it works
Formula
Aₚ = πD²/4; Aₐ = π(D² − d²)/4; v = Q/A; t = s/vQ = v × πD²/4Q = v × π(D² − d²)/4Piston area Aₚ = πD²/4; rod area Aᵣ = πd²/4; annular area Aₐ = Aₚ − Aᵣ. Speed v = Q/A, travel time t = stroke/v, and required flow Q = vA. Calculation uses m, m³/s, m² and s. GPM means US gallons per minute.
Worked example
With an 80 mm bore, 40 mm rod, 30 L/min inlet flow and 500 mm stroke, extension speed is 99.47 mm/s and retraction speed is 132.63 mm/s. Travel times are 5.03 s and 3.77 s. A target extension speed of 100 mm/s requires 30.16 L/min.
How it works
Extension uses the full piston area; retraction uses the smaller annular area around the rod. At equal inlet flow, a cylinder with a rod retracts faster. Required flow is the target speed multiplied by the chamber's effective area.
Common questions
Why is retraction faster at the same flow?
The rod reduces the chamber's effective area. The same volume of fluid therefore moves the piston farther each second during retraction.
Can I calculate flow from a target speed?
Yes. Choose Extension flow or Retraction flow and enter the bore, rod diameter and target speed. The result is the required inlet flow for the chosen direction.