Spring Calculator
Professional
The professional spring-design engine engineers and manufacturers have trusted for decades, re-built to run in any browser — with nothing to install.
Nothing to install · Windows, Mac & Linux · Runs in any modern browser
Stresses, fatigue life by Goodman, relaxation, tolerances and full operating data — the proven IST engine, unchanged. Design compression, extension and torsion springs today, with more spring types on the way.
A fully interactive 3D model of your spring that redraws the instant you change a value. Rotate it, zoom in, and inspect the geometry from any angle as you design.
Set the loads, rates and dimensions you need to hit, and the Solver searches automatically for spring designs that satisfy every constraint — turning hours of iteration into seconds.
Share a read-only link with a customer or colleague. They open the spring, its 3D drawing and every calculated result directly in their browser — with no login and nothing to install.
Export precise geometry to your CAD system as STEP or IGES, and generate print-ready PDF reports of the full design — documentation your team and customers can rely on.
The full professional tool, running wherever you do — office, workshop or factory floor.
Open a browser and start designing. No downloads, licences to deploy or IT tickets.
Every improvement and engine update reaches you the moment you load the page.
If it runs a modern browser, it runs the calculator — the same professional tool on every operating system.
£40 per spring type per month, or all three for £100. No minimum subscription period.
Add or remove spring types at any time. More spring types coming — existing subscriptions unaffected.
Join the engineers and manufacturers putting the world’s favourite spring calculator to work — no installation required.
Start designing
