Panel Wiring Length Calculator

Work out panel wiring length instantly with clear inputs, formula shown and shareable results.

About Panel Wiring Length Calculator

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.

Formula

Wire estimate

length = terminals x average run x cores x (1 + waste)

Worked example

With the default values below, Panel Wiring Length Calculator returns Wire required of 234.60. Change any input above and every figure here is recalculated in your browser.

Inputs used

Terminals to wire: 240 terminals
Average wire run: 0.85 m
Cutting and dressing waste: 15 %
Cores per connection: 1 cores

Results

Wire required: 234.60 m
Effective length per terminal: 0.98 m
Waste included: 30.60 m
100 m reels needed: 3 reels

Step by step

1Values used
2Wire estimate
3Wire required= 234.60 m
4Effective length per terminal= 0.98 m
5Waste included= 30.60 m
6100 m reels needed= 3 reels

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How do I estimate the average run?

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.

Why is waste so high?

Ferruling errors, re-dressing, wires cut short during rework and colour changes. Ducted panels with careful measurement can get below 10%.