A SMALL TOOL WITH ONE JOB
About Helixlength.
Helixlength performs one calculation: the ideal centreline material length of a constant-radius, constant-pitch circular helix.
It distinguishes inside, outside and centreline diameters, supports fractional turns and zero-pitch arcs, and keeps straight tails and entered allowance separate. An unwrapped one-turn diagram makes the underlying right triangle visible.
This is geometric arithmetic, not a spring-design, electrical-rating or fabrication-approval service. It does not predict stretching, springback, bend deductions or full physical clearance. Local reports preserve the inputs and limits without an account.
Free to use
There is no subscription, checkout or account. The calculator is part of an independently operated collection of free planning tools. Each site focuses on one calculation so its assumptions stay easy to inspect.
How the tool is maintained
The calculation method is described in the worked guide. Automated checks cover conversion factors, example results and invalid inputs. A model can still miss a practical detail; use the guide to decide whether its assumptions fit your situation.
Corrections and questions
For a reproducible calculation problem or a privacy enquiry, use our shared portfolio contact. Include the inputs and expected result. No telephone call is needed.