Fence Waste Factor: How Much Extra to Order

The short answer

Order about 10 percent extra pickets and fixings for a straight, level run built from standard 8.00 ft bays. Raise that to 15 percent when the line is angled, stepped on a slope, or includes gates, where cut pickets cannot be reused. Round up to whole pickets and whole boxes of fixings. Panels are normally excluded from the waste allowance because a standard 8.00 ft panel that is damaged or mis-set is replaced whole, not trimmed, and the calculator already counts panels per bay rather than per picket.

The calculator handles the base quantities: posts at 8.00 ft spacing, panels or palings, two rails per bay, concrete bags and gates. The waste factor is applied afterwards to the picket and fixing lines only. Confirm the exact allowance with your supplier before ordering, since pack sizes and return policies differ by yard.

Worked example: 100 ft straight run

Take a 100 ft run at the default 6.00 ft height with 8.00 ft post spacing. That gives 13 posts and 12 bays. At 89 mm pickets with a 13 mm gap, each picket plus gap covers about 102 mm, or roughly 4.02 in, so one 8.00 ft bay needs about 24 pickets. Twelve bays therefore need about 288 pickets, plus 24 rails.

A 10 percent allowance adds 29 pickets, so order 317. Fixings scale the same way: if the base count is 288 pickets at two fasteners each, that is 576 fasteners, and 10 percent takes it to 634, rounded up to the next box size. The calculator gives the 288 and 24 figures directly; the extra 29 pickets is the step you add yourself.

Why panels are left out

A panel is a fixed 8.00 ft unit. If one is cut, it is because the run is not a whole number of bays, and that shortfall is already handled by the calculator's bay count and the final partial bay. Adding 10 percent on top would double-count it. Damaged panels are a replacement issue, not a waste issue, and most yards will exchange an undamaged panel, so carrying spares is a choice rather than a rule.

The same logic applies to posts: they are set at fixed 8.00 ft centres and are not cut to length in normal builds, so a waste percentage adds cost without reducing risk. Keep the allowance on pickets, rails cut to fit, and fixings, which are the items actually lost to knots, splits, mis-cuts and dropped screws.

When to go higher

Step up to 15 percent, and occasionally 20, on three layouts. First, sloped ground where pickets are trimmed to follow the grade, leaving offcuts too short to use. Second, angled or curved runs where each bay meets at a non-square corner and the end pickets are ripped. Third, runs with gates, since gate frames and hinges consume pickets and hardware outside the bay count.

For a 100 ft run with two gate openings and a 2 ft fall across the line, the 29-picket allowance becomes about 43. Ask your supplier whether pickets are sold singly or in bundles, because a bundle price can make a slightly larger order cheaper than topping up later. Local permitting and inspection requirements for post depth and footing size vary by jurisdiction; confirm those with your local building department, not with the calculator.

Ordering and checking

Add the waste figure to the picket and fixing lines, keep panels and posts at the calculated count, and note the total on the order. Check the delivery against the count before signing, since shortages found after the crew starts cost more in time than the extra pickets would have. Store spares flat and dry so they stay usable for repairs.

If you are unsure, run the calculator twice, once with the straight-run assumption and once with the gated or sloped assumption, and order the higher picket figure. The difference is usually a few dollars of pickets against a day of delay.

Quick reference

Straight, level run: 10 percent on pickets, rails and fixings. Sloped, angled or gated run: 15 percent, up to 20 percent on tight curves. Panels and posts: no waste allowance, order the calculated count. Always round pickets up to whole units and fixings up to whole boxes, and confirm pack sizes and exchange terms with your supplier before paying.

Frequently asked questions