How Many Fence Panels and Posts Do I Need?

Updated October 31, 2026

A fence order is a count of panels and posts. You need the length of the run, the width printed on the panel, and the spacing you will actually set the posts to. A gate takes the place of a panel. It does not remove the posts on either side of the opening.

Measure the line the fence will follow

Measure in feet along the line you will build, not across the yard on a diagonal. A corner ends one run and starts the next. Add the runs after you have counted each one, or enter a single total when every side uses the same panel and the same spacing.

A gate opening is still part of the length. Mark it as a gate so the panel that would have filled that bay comes off the panel order. Leaving the gate out of the length, and also subtracting a gate, drops the panel twice.

Posts and panels are two divisions

Sections come from the fence length divided by the post spacing, rounded up to a whole section. Posts are that section count plus one, because the run needs a post at the far end.

Panel bays come from the fence length divided by the panel width, also rounded up. Panels to install are the bay count minus the gates. When the panel width and the post spacing are the same number, the bay count and the section count match. When they differ, keep them separate. Do not average them into one spacing.

A 96 foot run with 8 foot panels and one gate

Post spacing 8 feet, which matches a common prefab panel.

• Sections: 96 ÷ 8 = 12. Posts: 12 + 1 = 13.
• Panel bays: 96 ÷ 8 = 12. Panels before waste: 12 − 1 gate = 11.

A length that does not divide evenly still rounds up. 100 feet at the same 8 foot spacing is 12.5 sections, which becomes 13 sections and 14 posts. You cannot set half a bay.

Waste applies to panels, not to posts

The waste choices are 0, 5, 10, 15, and 20 percent. They change the panel order only. The post count stays at sections plus one.

• 5% — exact prefab bays, and you can go back to the same stack if one panel is damaged.
• 10% — the default. On the 11 panel example, 11 × 1.10 = 12.1, which rounds up to 13 panels to buy.
• 15% or 20% — several short runs, or a slope where you expect to cut panels.

With no gate on the same 96 foot run, panels before waste are 12. At 10 percent that is 13.2, and the order rounds up to 14 panels. Posts are still 13. If you want a spare post, add it yourself. The waste field will not add it.

What the count leaves out

Each post needs a footing. That volume is a hole, not a rectangular slab. Do not type the fence length into the concrete calculator and read the result as post concrete. The slab notes explain a different shape: How Much Concrete Do I Need for a Slab?.

A gate kit, hinges, and rails (when you are not buying prefab panels) are separate from the panel count. If you type a panel price and a post price, the cost line is those prices times the recommended panels and the post count. It is not an installed price, and it does not include the footing material.