Enter the total length of your fence run, choose your post spacing, number of rails, and picket dimensions. The calculator instantly outputs the number of posts, rails, pickets, and even the concrete you'll need for setting posts. It's designed for wood privacy fences but works for picket fences, split rail, and vinyl too — just adjust the spacing and picket gap.
Standard post spacing is 8 feet for most wood privacy fences. If you're in a high-wind area or using heavier materials, 6-foot spacing adds rigidity. For vinyl or metal fencing, 8–10 feet is common. Shorter runs between corners and gates will naturally create smaller sections.
For a standard 6-foot privacy fence, 3 rails (horizontal boards running between posts) is the norm. For shorter fences (4 feet), 2 rails is fine. If you're building a horizontal fence where the pickets run sideways, you'll need 4–5 support rails depending on your design.
For a full privacy fence, use a gap of 0 to ¼ inch between pickets — this accounts for wood expansion in humid weather. For a semi-private look, increase the gap to 1–2 inches. Our calculator's picket gap field lets you experiment with different looks.
Standard spacing is 6–8 feet for wood fences and 8–10 feet for vinyl or metal. Shorter spacing means a sturdier fence but more posts to set.
For a 6-foot privacy fence, use 3 rails. For a 4-foot picket fence, 2 rails is standard. Horizontal fences may use 4–5 rails.
A typical 4×4 post needs about 1–2 bags of 80 lb concrete, depending on hole depth and diameter. Our calculator uses 1.5 bags per post.
The rule of thumb is 1/3 to 1/2 of the post height above ground. For a 6-foot fence, dig 2–3 feet deep. Always go below the frost line in cold climates.