Fence Calculator
Estimate a fence from your yard's shape. Enter the length or trace the fence line over an aerial photo, set your post spacing and height, and get the posts, panels, rails, and bags of concrete — with the post-hole depth and cross-section worked out.
Fencing as part of a bigger project? Open the Yard Planner → to trace the fence and your beds together and total everything.
How the fence calculator works
A fence estimate comes down to how you break the run into sections. Posts sit at both ends and every 6–8 feet in between; panels or pickets fill the gaps; rails span between posts (usually two or three per section). Get the post count right and everything else follows.
In Streamlined mode you enter a total length and the calculator divides it into sections and counts posts, panels, and rails. In Advanced mode you trace the fence line over an aerial photo — around corners and along property lines — and it totals the real run, places the posts, and shows a post-hole cross-section so you can see how deep to dig and how much concrete each hole takes.
Post holes are the part people underestimate. A post should be buried about one-third of its above-grade height (deeper in frost-prone ground, below the frost line), and each hole takes a surprising amount of concrete once you account for the void around the post. The calculator sizes the holes and totals the bags.
How to use this calculator
- Choose Streamlined (enter a length) or Advanced (trace the fence line over an aerial photo, setting the scale on a known distance first).
- Set the post spacing (6–8 ft is typical) and the fence height.
- Review the post, panel, and rail counts — the calculator splits your run into sections and counts each part.
- Check the post-hole cross-section for the buried depth and concrete per hole; adjust hole depth for frost or soft soil.
- Add a buying margin for waste and cuts, then read the full materials list from the results panel.
Tips for a fence that lasts
Bury posts a third of their height
A 6 ft fence wants roughly 2 ft of post in the ground — and deeper than your local frost line, or heaving will push the posts up over winter. Corner and gate posts should go deeper still.
Set line posts first, then corners
Corners and gates carry the load, so set them in concrete first and string a line between them. Line posts follow the string for a straight, evenly-spaced run.
Don't forget gate and corner posts
Every corner, end, and gate needs its own post — they're easy to miss when you divide length by spacing. Trace mode places them automatically; in Streamlined mode, add one per corner and gate.
Buy 10% extra pickets and rails
Cuts, warped boards, and the odd mistake add up. Order about 10% more pickets and rails than the exact count, especially if you're doing the work yourself.
Frequently asked questions
How many fence posts do I need?
For a straight run, plan one post about every 8 feet plus a closing post — an 80 ft fence needs about 11 posts. Add a post for every corner, end, and gate. The calculator counts these automatically when you trace the line.
How many fence panels or sections do I need?
Divide your total length by the section length (commonly 8 ft) and round up. A 50 ft fence needs about 7 eight-foot sections. Pickets are counted per section from the picket width and gap.
How deep should fence posts be?
Bury about one-third of the post's above-grade height — roughly 2 ft for a 6 ft fence — and always below your local frost line so winter heave doesn't lift them. Corner and gate posts go deeper. The cross-section shows the buried depth and concrete per hole.
How much concrete does a fence post take?
It depends on hole diameter and depth and the post size, but a typical 8–10 in wide × 24 in deep hole with a 4×4 post takes roughly 1–2 sixty-pound bags. The calculator totals the bags for your hole size and post count.
How do I measure my fence line?
Walk the line and measure it in feet, or upload an aerial photo of your property, set the scale on a known length, and trace the fence — including corners — and the calculator totals the linear feet and places the posts.