What does the gas spring calculator calculate?

It estimates a compression gas spring force and mounting geometry for a rigid hinged door or flap. It also models the panel through its travel so you can review spring length, stroke and manual effort before requesting an engineering review.

Can I use metric or imperial measurements?

Yes. The calculator accepts metric and imperial units. Use one system consistently and measure from the hinge centre and connector pivot centres shown in the tool.

Is the calculated gas spring ready to install?

No. The result is a preliminary sizing estimate. Gemini must confirm the mounting points, force, hardware, operating environment and safety requirements before a spring is selected for installation.

When should I contact Gemini instead of relying on the calculator?

Ask Gemini to review offset hinges, flexible panels, off-centre loads, tension springs, unusual motion, high-cycle duty or any application where a failure could create a safety risk.

Engineering tool

Gas Spring Calculator

Estimate the compression-spring force and mounting geometry for a rigid hinged door or flap. The calculator visualizes the full movement, works in metric or imperial units, and prepares a preliminary result for Gemini's engineering review.

Open the calculator See what to measure

Built for rigid hinged doors and flaps using compression gas springs.

What the calculator does

Turn a moving panel into the measurements needed for a useful first estimate.

Estimates spring force: Models the door weight, balance point, handle position and desired manual effort to estimate a spring force.
Checks the full travel: Shows the application moving from closed to open so proposed mounting geometry can be reviewed throughout the swing.
Prepares the next step: Carries the preliminary result into the configurator and gives Gemini the inputs needed for engineering review.

What to measure before you start

Accurate measurements make the preliminary result more useful.

Door or flap dimensions: Measure the length from the hinge centre to the far edge, the full thickness at the hinge and the position of the hinge pivot.
Total moving weight: Include the panel, handle, hardware, glass and every other component that moves with the door or flap.
Centre of gravity: Measure from the hinge centre. For a uniform panel, half its length is a useful starting estimate.
Handle position: Measure from the hinge to the normal hand position so the calculator can estimate the effort at the handle.
Closed and open angles: Record the panel angle at both ends of its travel and whether the motion is clockwise or counter-clockwise.
Number of springs: Choose how many identical springs will share the load. The model assumes that the load is divided evenly.

How to use the calculator

Three steps from application geometry to a reviewable result.

Describe the application
Choose the closest door orientation, then enter its dimensions, weight, balance point, handle position and travel angles.
Review mounting and travel
Use the live diagram to assess the proposed spring position through the full movement and select the required end connections.
Send the result for review
Carry the preliminary result into Gemini's configurator or send the calculation to our team for confirmation before installation.

Preliminary sizing needs engineering review

A calculation is a starting point, not installation approval.

The calculator uses a planar compression-spring model for a rigid door or flap. Seal friction is not included because it varies by spring construction. Final selection also depends on the operating environment, duty cycle, mounting hardware and safety needs.

Contact Gemini for offset hinges, flexible doors, off-centre loads, unusual movement or tension-spring applications. For a conventional hinged panel, open the calculator and send the result to our team before ordering or installing a spring.

Calculate a gas spring

Calculator or configurator?

Use the tool that matches what you already know.

Tool	Use it when	What you provide	Next step
Gas spring calculator	You need to size a spring for a hinged door or flap.	Load, geometry, travel and desired manual effort.	Review the result, then configure or contact Gemini.
Gas spring configurator	You already know the required size, force and options.	Dimensions, material, end fittings and accessories.	Build a specification for Gemini to review.