Structured Cabling Run Estimator

How much Ethernet cable a set of drops needs, and how many boxes to order.

Data drops

Average run per drop (m)

Riser per drop (m)

Slack allowance (%)

Cable box size

Patch cords per drop

One drop is one outlet: a wall plate at the desk end plus its port at the patch panel.

Average horizontal distance from the outlet to the wiring closet, before slack. Measure a few representative rooms rather than guessing.

Extra vertical distance each cable travels, for example up a riser to a closet on another floor. Use 0 when the closet is on the same floor as the outlets.

Extra cable for routing around obstructions, drip loops and termination tails. Ten percent is a common allowance; a difficult route needs more.

Boxes are bought whole, so the estimate rounds up to the next full box at this size.

Patch cords are counted separately from the boxed cable: typically one at the outlet and one at the panel.

The estimate is ordinary arithmetic on a site assumption: every drop is charged the same average run plus riser distance, increased by the slack allowance, and whole boxes are then rounded up. It does not survey a building, choose a cable category, check conduit or tray fill, or predict how much cable a failed pull wastes; those need a walk-through and the cable manufacturer's box lengths. It runs entirely in your browser with no storage, uploads or network access.