Hydraulic Cylinder Calculator

Calculate cylinder force, speed, flow requirements and system parameters for hydraulic applications.

Application Presets

Industrial Machine
Standard industrial applications
Mobile Equipment
Construction, agriculture
High-Pressure System
Heavy-duty applications
Hydraulic Cylinder Diagram
Port A Port B Piston Rod Bore Diameter (D) Rod Diameter (d)
Force Calculator
Speed Calculator
Flow Calculator
Typical range: 25-400 mm (1-16 in)
Please enter a valid bore diameter between 10 and 500
Typically 0.5-0.7 × bore diameter
Please enter a valid rod diameter between 5 and 250
Typical range: 70-350 bar (1000-5000 psi)
Please enter a valid pressure between 10 and 700
%
Typical efficiency: 80-95%
Please enter a valid efficiency between 50 and 100
:1
Typical: 1.5-2.5 for static loads, 3-5 for dynamic loads
Please enter a valid safety factor between 1 and 5
Typical range: 25-400 mm (1-16 in)
Please enter a valid bore diameter between 10 and 500
Typically 0.5-0.7 × bore diameter
Please enter a valid rod diameter between 5 and 250
Typical range: 5-200 L/min (1-50 gpm)
Please enter a valid flow rate between 1 and 500
%
Typical range: 90-98%
Please enter a valid efficiency between 80 and 100
Typical range: 50-3000 mm (2-120 in)
Please enter a valid stroke length between 10 and 5000
Typical range: 25-400 mm (1-16 in)
Please enter a valid bore diameter between 10 and 500
Typically 0.5-0.7 × bore diameter
Please enter a valid rod diameter between 5 and 250
Typical range: 0.05-0.5 m/s (2-20 in/s)
Please enter a valid speed between 0.01 and 2
%
Typical range: 90-98%
Please enter a valid efficiency between 80 and 100
Maximum: 20 cylinders
Please enter a valid number between 1 and 20
%
Percentage of cylinders operating simultaneously
Please enter a valid percentage between 0 and 100
Calculating...
Hydraulic Cylinder Results

Understanding Hydraulic Cylinders

Hydraulic cylinders convert fluid pressure into linear mechanical force and motion. They are essential components in hydraulic systems used in construction equipment, manufacturing machinery, and many other applications.

Key Insight: The force generated by a hydraulic cylinder is directly proportional to the fluid pressure and the piston area. Speed is determined by the flow rate and the piston area.

Cylinder Types and Configurations

1

Single-Acting Cylinders: Fluid pressure acts on one side of the piston only. Return is accomplished by gravity, a spring, or external force. Commonly used in applications where the load provides the return force.

2

Double-Acting Cylinders: Fluid pressure can be applied to either side of the piston for both extension and retraction. Most common type in industrial applications.

3

Telescopic Cylinders: Multiple stages that collapse into each other, providing a long stroke from a compact retracted length. Used where space is limited.

4

Rodless Cylinders: The piston moves along the cylinder barrel without an external rod. Offer long strokes in compact spaces.

Key Formulas

  • Force (Extension): F = P × Apiston × η
  • Force (Retraction): F = P × (Apiston - Arod) × η
  • Speed (Extension): v = Q / Apiston × ηv
  • Speed (Retraction): v = Q / (Apiston - Arod) × ηv
  • Flow Requirement: Q = A × v / ηv
  • Power: Phyd = F × v or Phyd = p × Q

Where: F = Force, P = Pressure, A = Area, Q = Flow rate, v = Speed, η = Efficiency, ηv = Volumetric efficiency

Common Cylinder Sizes and Capacities

Bore Size (mm) Rod Size (mm) Extension Force at 150 bar (kN) Retraction Force at 150 bar (kN) Typical Applications
40 20 18.8 14.1 Small machinery, clamping
63 32 46.7 35.0 Industrial equipment, presses
100 50 117.8 88.4 Construction machinery, lifts
160 80 301.6 226.2 Heavy equipment, large presses
250 140 736.3 515.4 Mining equipment, large lifts

Design Considerations

  • Pressure Rating: Select cylinders rated for at least 1.5 times the maximum system pressure
  • Rod Size: Ensure adequate rod diameter to prevent buckling under compressive loads
  • Mounting Style: Choose appropriate mounting (clevis, flange, trunnion) for the application
  • Seal Selection: Match seals to fluid type, temperature, and pressure requirements
  • Cushioning: Consider cushioning options for high-speed applications to reduce impact
  • Stroke Length: Account for rod elongation under load in long-stroke applications

Safety Consideration: Always install pressure relief valves in hydraulic systems to prevent overpressure situations. Cylinders should never be operated beyond their rated pressure, as this can cause catastrophic failure.

Frequently Asked Questions

During retraction, the effective piston area is reduced by the cross-sectional area of the rod. Since force is proportional to area (F = P × A), the retraction force is lower than extension force for the same pressure. The difference depends on the rod-to-bore ratio.

Friction is accounted for through the efficiency factor (typically 85-95%). This factor represents losses due to seal friction, internal leakage, and other mechanical losses. For precise calculations, consult manufacturer data for specific cylinder models.

Mechanical efficiency accounts for friction losses that reduce output force. Volumetric efficiency accounts for internal leakage that reduces effective flow rate. For force calculations, use mechanical efficiency. For speed/flow calculations, use volumetric efficiency.

First, determine the required force considering the load and safety factors. Then calculate the bore size needed to generate that force at your system pressure. Next, determine the rod size based on buckling considerations for compressive loads. Finally, verify that the selected cylinder can achieve the required speed with your available flow rate.

Cylinder speed is primarily determined by flow rate and piston area. Other factors include system pressure (affects pump delivery), fluid viscosity (affects flow resistance), temperature (affects viscosity), and cylinder condition (wear increases internal leakage). For consistent speed, consider using flow control valves.