Work out panel wiring length instantly with clear inputs, formula shown and shareable results.
Panel wire estimating is terminal count times average run length times cores, plus a waste allowance for cutting, dressing and rework. Fifteen percent is typical for a neatly ducted panel; more for point-to-point wiring or where colour coding forces short offcuts.
Wire estimate
length = terminals x average run x cores x (1 + waste)
Take the mean of a representative sample: door-mounted devices are long runs, DIN-rail to DIN-rail are short. 0.6-1.2 m is typical for a medium panel.
Ferruling errors, re-dressing, wires cut short during rework and colour changes. Ducted panels with careful measurement can get below 10%.