Sizu Home › Calculators › Fence Post Counter
Opens on the book's own fence. Change any number to your own and press Calculate.
The legs: straight runs between corners or gates, center to center
Gates
Enter the run and press Calculate.
The formula
- Bays on a leg = leg ÷ largest spacing, rounded up (the spacing is a maximum)
- Real spacing = leg ÷ bays
- Open run: posts = bays + 1. Closed loop: posts = bays (the last bay ends on the first post)
- Each gate is a bay of its own: gate posts center to center = opening + half of each gate post
The book's worked example, Chapter 1. Route A runs 7.2 m of fence at 2.4 m: 3 bays, plus the gate bay, so 4 bays and 5 posts. Route B, at 1.8 m: 4 + 1 = 5 bays, 6 posts. The gate posts stand 1,089 mm apart on Route A (1,114.5 mm with Route B's 6x6 hinge post), and the whole line is 8,378 mm outside to outside.
Corners are shared: two legs that meet at a corner share its post, which is why you count bays and add one at the very end. Prices are illustrative US home-center prices from October 2026, shown without a currency sign; put in your own. Everything stays in your browser: no sign-up, nothing stored.