A fence picket calculator answers the question the material order depends on: how many pickets does the run take at this picket width and this gap. The arithmetic is the run in inches divided by the picket width plus the gap, and it changes with every choice a customer makes, from a privacy fence with no gap to a picket fence with a wide one to a board on board fence where the second course overlaps the first. This page works the picket count for the common cases, per 8 foot section and for a whole run, so the take-off on a fence estimate is a count rather than a guess, and points at the free fence estimate tool on this site that prices the run from that count and the contractor's own rates. No figure here is a market price.
The formula, and why the gap matters more than the picket
Pickets per run equals the run length in inches divided by picket width plus gap. A 5.5 inch picket with a 2.5 inch gap takes 8 inches of run each, so an 8 foot section, 96 inches, takes 12 pickets and a 160 foot run takes 240. Close the gap to zero for a privacy fence and the same section takes 17.5 pickets, which is 18 cut from 18 boards. A picket fence calculator that ignores the gap is out by a third before the first board is nailed.
Board on board: two courses, one overlap
A board on board fence runs a second course over the gaps in the first, so the count is worked twice. With 5.5 inch boards set at a 5.5 inch gap the first course of an 8 foot section takes 8.7 boards, and the second course covering the gaps takes the same again, so the section takes 17 to 18 boards depending on where the panel starts and ends. Enter the overlap you actually build and the tool counts both courses; the answer to how many pickets per 8 foot section board on board is always roughly double the single course.
Spacing the other way round: from a fixed count to the gap
A picket fence spacing calculator works backwards: the customer wants an even look, so the crew fixes the picket count per section and solves for the gap. With 12 pickets of 5.5 inches in a 96 inch section the boards take 66 inches, leaving 30 inches across 11 gaps, which is 2.73 inches each. The tool takes either the gap or the count and returns the other, so the layout the customer approved is the layout the crew builds.
From the count to the estimate
The picket count sets the material line, but the estimate also needs the posts from the spacing, the rails, the gates counted each, labor per foot and any removal. The free fence estimate tool on this site works those from the contractor's own costs and markup and ends on the price per linear foot; TakeoffDeck Pro keeps the estimate against the customer with the count that was quoted. This page publishes no lumber price: every figure in the estimate is the contractor's.
Questions people ask about fence picket calculator
How many pickets do I need for a 160 foot fence?
Run in inches divided by picket width plus gap. At 5.5 inch pickets with a 2.5 inch gap that is 1,920 divided by 8, which is 240 pickets; with no gap it is 349. Board on board roughly doubles the count.
How many pickets per 8 foot section?
A 96 inch section takes 12 pickets at 5.5 inches with a 2.5 inch gap, 18 at 5.5 inches with no gap, and about 17 to 18 board on board. Enter your own width and gap for your own count.
Does the privacy fence calculator include the rails and posts?
The picket count is the material between the posts. The fence estimate tool adds the posts from the spacing, the material per foot, the gates, the labor and any removal, and prices the run from your rates.