Outdoor project planning

Fence Calculator

Turn a property perimeter into a practical material estimate. Subtract gates and customize spacing to match your fence system.

Calculate your estimate

Enter the fence dimensions above.

How much fence do I need?

Answer first: start with the length of the boundary you actually plan to fence, then subtract gate openings. This calculator converts that net length into approximate posts and panels.

Planning tip

If you measured your full property perimeter on the map, do not automatically assume every foot needs fencing. Exclude unfenced road frontage, shared boundaries you are not replacing, water edges or other sections that are outside the project scope.

Before digging: confirm the legal boundary and use the applicable utility-location service before setting posts.

Fence calculator formula

The calculator first subtracts gate openings from the length you plan to fence:

Net fence length = planned fence run − gate openings

It then estimates panels as net fence length ÷ panel width, rounded up. Posts are estimated as net fence length ÷ post spacing, rounded up, plus an end post. Real layouts can require extra posts at corners, gates, changes in direction and transitions.

Worked example

Boundary/run entered400 ft

Minus 12 ft of gate openings = 388 linear ft of fence.

8 ft spacing/panels~50 posts · 49 panels

A starting quantity only; corners and gate framing can increase the count.

Perimeter is not always fence length

If you measured an entire property, decide which boundary segments are actually part of the fence project. A road frontage, shared existing fence, water edge or open driveway entrance may not belong in the material order.

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.

Should I subtract gate width?

Yes for panels or continuous fence material. Gate posts may still be needed, so final post counts should be adjusted to the actual layout.

Does this calculator include concrete?

Not yet. The launch version estimates fence length, posts and panels; post-hole concrete is a planned expansion.