Fence Calculator
Turn a property perimeter or fence run into posts, panels, concrete bags and an optional material-cost estimate. Gate openings and extra corner/gate posts stay under your control.
Calculate your fence estimate
How much fence do I need?
Answer first: start with the boundary you actually plan to fence, subtract gate openings, then divide the remaining run by your panel width and post spacing. AcreSketch also lets you add extra corner/gate posts and estimate concrete bags.
Planning tip
If you measured your full property perimeter on the map, do not automatically assume every foot needs fencing. Exclude unfenced road frontage, existing shared boundaries, water edges and any section outside the project scope.
Fence calculator formula
The calculator first subtracts gate openings from the planned fence run:
Net fence length = planned fence run − gate openings
Panels are net fence length ÷ panel width, rounded up. Base posts are net fence length ÷ post spacing, rounded up, plus an end post. Any extra corner/gate posts you enter are then added. Concrete bags are estimated from your bags-per-post input.
Worked example
Minus 12 ft of gate openings = 388 linear ft of fence.
Then add corner and gate posts that the straight-run formula cannot know.
Optional cost estimate
Enter your local panel, post and concrete-bag prices to get a rough listed-material subtotal. It deliberately excludes gate hardware, fasteners, labor, tax and delivery because those vary widely by fence system and supplier.
Frequently asked questions
How many fence posts do I need for 400 feet?
At 8-foot spacing, a straight run needs roughly one post per 8 feet plus an end post. Corners, gates and layout changes can increase the actual count.
How do I measure linear feet for a fence?
Measure each boundary section you intend to fence and add those lengths. Linear feet measure length, not square footage. Enter that total as the planned run and enter gate openings separately; the calculator subtracts the gates once.
How many feet of fence do I need for 1 acre?
A square one-acre lot has about 834.84 ft of perimeter. Its side is √43,560 ≈ 208.71 ft. A 100 × 435.6 ft rectangle is also one acre but has a 1,071.2 ft perimeter. Fence only the sections in your project, then account for gates. Compare acreage shapes and perimeter. Area conversion reference: NIST unit definitions.
How many fence panels or boards do I need?
For a simple straight run, panels = net fence length ÷ panel width, rounded up. A 100 ft run with a 4 ft gate leaves 96 ft: twelve 8 ft panels before layout adjustments. Board count additionally needs the actual board width, gap and fence style; panel count alone cannot give it.
Should I subtract gate width?
Yes for panels or continuous fence material. Gate posts are still needed, which is why the calculator includes an extra-post field.
Does this calculator include concrete?
Yes. Enter the number of bags you expect per post and AcreSketch estimates the total bag count. Verify hole size, frost depth, soil conditions and bag yield for the actual build.