Gas Spring Calculator

Size and select gas springs for hinged panels. Choose from standard catalog springs, let the calculator find the optimal force, or manually specify any configuration.

Inputs

Door Properties

Door Mass (kg) ?

Door Length (m) ?

Open Angle (°) ?

Number of Springs

Mounting Points

Door Mount ?

Frame X (m) ?

Frame Y (m) ?

Spring Selection

Loading catalog...

0 springs shown. Click to select.

The calculator will determine the optimal spring force to minimize hand effort, then find the closest matching standard spring from the catalog.

Force per Spring (N)

Configure your door and click Calculate to get spring recommendations.

GOOD ZONE Easy to operate

Peak: -- N

Mechanism & Force Zones

Angle: 0°

Good (<20N)

OK (20-40N)

High (40-60N)

Excessive (>60N)

Drag the frame mount point to see how position affects hand force

Spring dimensions and forces will update as you adjust parameters

Moment Equilibrium

Red = Door moment (gravity). Green = Spring moment. Where they cross, the door is balanced.

Hand Force Required

Positive = push up needed. Negative = hold down. Zero = balanced.

How to Use This Calculator

Enter door specifications: Mass, length, and opening angle
Choose selection mode:
- From Catalog: Pick a specific standard spring
- Auto Optimize: Let the calculator find the best spring
- Manual Entry: Specify any force value
Adjust mounting points: Either type values or drag in the visualization
Review the force zones: Green = easy, Yellow = OK, Orange = hard, Red = excessive

Pro Tip

Use the visualization tab to drag the frame mount point around and watch the force zone change in real-time. Find a green zone position that works for your installation.

Force Zone Guide

The colored zones indicate how much effort is needed to operate the door at its heaviest position:

GREEN: Good (<20N)

Easy one-handed operation. The door feels light and well-balanced. Ideal for frequent use.

YELLOW: Acceptable (20-40N)

Moderate effort required. Still comfortable for most users but may tire with repeated use.

ORANGE: High (40-60N)

Noticeable effort required. May need two hands. Consider increasing spring force or adjusting mount positions.

RED: Excessive (>60N)

Difficult to operate. Risk of injury or dropping the door. Springs are undersized or poorly positioned.

Standard Gas Spring Catalog

The catalog contains over 100 standard gas springs organized by series:

6/15 Series (Light Duty)

6mm rod, 15mm tube. Force range 50-400N. For cabinet doors, small hatches.

8/18 Series (Medium Duty)

8mm rod, 18mm tube. Force range 80-750N. For toolbox lids, equipment covers.

10/22 Series (Heavy Duty)

10mm rod, 22mm tube. Force range 100-1200N. For trap doors, heavy hatches.

14/28 Series (Extra Heavy)

14mm rod, 28mm tube. Force range 200-2500N. For large industrial doors.

Stroke Rule

Always choose a spring with stroke ≥ your required stroke + 10mm margin. The compressed length must fit your installation.

Physics of Gas Spring Selection

Door Moment (Gravitational) $$M_{door}(\theta) = m \cdot g \cdot L_{cg} \cdot \cos(\theta)$$

Spring Moment $$M_{spring}(\theta) = n \cdot F \cdot r_{\perp}(\theta)$$

Required Hand Force $$F_{hand} = \frac{M_{door} - M_{spring}}{L_{hand}}$$

The key insight is that both the door moment and spring moment vary with angle, but differently. No single spring force achieves perfect balance at all positions. The "optimal" force minimizes the peak hand effort across the full range of motion.