Fence Calculator
Everything to buy for a wood fence: posts and their length, rails, pickets or ready-made panels, and the concrete to set the posts, for any length, height, corners and gates.
Posts = fence length ÷ post spacing (8 ft), rounded up, + 1 per run + 1 per gate. A 6 ft privacy fence uses 3 rails per section and about 2.1 pickets (5½ in) per foot. 100 ft of 6 ft privacy fence with one gate needs about 15 posts, 39 rails, 230 pickets and 37 bags of 50 lb fast-setting concrete.
Fence materials for common lengths (6 ft privacy, 8 ft spacing)
| Fence length | Posts | Rails | Pickets | Fast-set bags |
|---|---|---|---|---|
| 50 ft | 8 | 21 | 115 | 20 |
| 100 ft | 14 | 39 | 230 | 35 |
| 150 ft | 20 | 57 | 344 | 50 |
| 200 ft | 26 | 75 | 459 | 64 |
| 300 ft | 39 | 114 | 688 | 96 |
Add one post per gate and one per extra run or corner. Post holes 10 in wide, 24 in deep (deeper below your frost line), with 6 in of gravel underneath.
Post length by fence height
| Fence height | In the ground | Post to buy |
|---|---|---|
| 4 ft | 24 in | 8 ft |
| 5 ft | 24 in | 8 ft |
| 6 ft | 24 in | 8 ft |
| 8 ft | 32 in | 12 ft |
Frequently asked questions
How many fence posts do I need?
Divide the fence length by the post spacing (usually 8 ft, or 6 ft in windy areas), round up, then add one for the end post of each run and one extra for every gate. 100 ft at 8 ft spacing is 13 posts, plus gate posts.
How many pickets do I need for a privacy fence?
Pickets are 5½ in wide, so a solid privacy fence takes about 2.2 per foot: 12 in ÷ 5.5 in. For 100 ft that is 219 pickets, plus 5% for splits and cuts.
How deep should fence posts be?
At least 2 ft, or about one-third of the post's length, and below the frost line in cold climates. A 6 ft fence usually uses 8 ft posts with 2 ft in the ground; an 8 ft fence needs 10–11 ft posts.
How many bags of concrete per fence post?
For a 4×4 post in a 10 in hole 24 in deep, about 1.9 cu ft of hole minus the post, roughly 2 to 3 bags of 50 lb fast-setting concrete or 2 bags of 80 lb mix. Use the fence post concrete calculator for other sizes.
How many rails does a fence need?
Two rails per section for fences up to 5 ft, three for 6 ft and taller, so pickets don't warp in the middle.
Run a garden club, nursery or landscaping site? Embed this calculator free with one line of code.
Related free tools
Fence Post Concrete Calculator
Bags of concrete per post hole or Sonotube footing.
Open tool →Deck Stain Calculator
Gallons of stain or sealer for deck floor, railings and stairs.
Open tool →Fence Stain Calculator
Gallons of stain for one or both sides of any fence style.
Open tool →Stair Calculator
Risers, treads, stringer length and code checks for any total rise.
Open tool →Sources and assumptions
Spacing, depth and rail counts follow common residential fence practice; check local codes, HOA rules and property lines before digging, and call 811 to mark utilities. Concrete yields from 50 lb fast-setting (0.375 cu ft), 80 lb (0.6 cu ft) and 60 lb (0.45 cu ft) bag labels. Prices are placeholders to edit.