Every WIAN LAN cable comes in a 305 m tangle-free box, which is 1,000 feet — the length the industry settled on decades ago. The question is how many runs that gives you, and the honest answer is: fewer than 305 divided by your run length.
The three things that eat cable
Slack at both ends. Allow 2 to 3 m at the rack end for dressing into the patch panel and 1 m at the outlet. That is 3 to 4 m per run before the cable goes anywhere.
The route is longer than the plan. Cable goes up to the ceiling, along the tray, down the wall. A 20 m straight-line distance is typically a 28 to 32 m pull. Measure the route, not the floor plan.
The last piece in the box. When 18 m is left and the next run is 22 m, that 18 m becomes patch leads or scrap. Budget 5 % of the box for this.
The quick formula
Runs per box ≈ 290 ÷ (average route length + 4 m). For an office with 30 m average routes: 290 ÷ 34 = 8.5, so 8 runs per box. For a camera job with 60 m routes: 290 ÷ 64 = 4.5, so 4 runs per box, with 50 m left for the short ones.
Use the metre markings
Every metre of WIAN cable is printed with a sequential length mark. Note the number on the jacket where the cable leaves the box at the start of a pull and again at the end; the difference is the exact run length, and the mark on the box tells you what is left. Write the start and end marks on the cable label at the patch panel — the next technician will know the run length without a tester.
A worked example
A 24-point office: 24 runs, average route 32 m after walking it with a wheel. 24 × 36 m = 864 m. That is 2.83 boxes, so order three boxes and you have about 50 m spare for the two runs that always turn out longer than drawn. Quote three boxes, not 864 m — cable is sold by the box and the client is better served by the spare than by a fourth site visit.
Box or reel? For long outdoor pulls where the whole 305 m goes in one or two runs, ask for the wooden reel. For office fit-outs with many short runs, the tangle-free box pays off every time you pull from the centre without a kink.