Chain Length Calculator

Interlocked jump rings overlap each other rather than lining up end to end, so a ring only advances the finished chain's length by a fraction of its full inner diameter once its neighbors are threaded through it. This calculator uses 70% as that average advancement factor, which is why linksNeeded comes from dividing chain length by (inner diameter × 0.7) rather than by the raw inner diameter.

The pattern factor multiplies how much wire each unit of finished chain length actually consumes: Simple (1-in-1) uses 1x, Double (2-in-2) uses 2x since two wire passes occupy each link position, and Byzantine uses 4x to account for the roughly four rings that interlock at each point in that weave. The factor is applied on top of the links-needed count, so a Byzantine chain of the same finished length needs four times the wire of a Simple chain built with identical ring size and gauge.

Wire Per Link is the length of wire required to form one jump ring — the circumference measured at the wire's center, π × (inner diameter + wire gauge) — which is the cut length before forming and closing a single ring. Links Needed is how many of those rings the finished chain requires; multiplying the two together (times the pattern factor) gives the total wire length.

The 70% overlap factor is an average behavior for interlocked rings, not a measurement of your specific ring gauge, closure tightness, or weave consistency — actual overlap varies slightly with how tightly you close each link. The extra wire buffer covers that variation plus normal forming losses (scrap ends, mistakes, re-cuts) so you don't run short mid-project.