Fence Calculator
Estimate posts, rails, and boards for any wood fence — privacy, picket, or split-rail — by total fence length.
Your Fence Estimate
- Measure total fence length — walk the perimeter with a tape or measuring wheel. Include all sides — subtract gate openings separately after you have a total.
- Select fence height — use the presets for the most common heights. Height determines board length, post length, and the number of rails needed.
- Set waste factor — 10% covers a typical yard with one or two gates. Increase for irregular lots, hillsides, or lots of corner posts.
- Enter cost per linear foot — or leave blank for a materials count only. Installed wood privacy fence runs $20-$45 per linear foot in most US markets.
- Check post count — results use 8-foot on-center spacing, which is standard for residential privacy fencing. For high-wind areas, use 6-foot spacing.
Breaking Down Fence Material Quantities
A wood fence is three components: posts, rails, and pickets or boards. Posts anchor every 6 to 8 feet on center — 8 feet is the standard for most residential privacy fences and lines up with pre-built 8-foot panels. Rails run horizontally between posts, two per section for standard 6-foot privacy fencing and three rails for 8-foot tall fencing. Pickets attach vertically to the rails to form the fence face.
For a 100-foot privacy fence at 8-foot spacing: 100 / 8 + 1 = 14 posts. Each 8-foot span needs 2 rails (16 rails total) and roughly 13-14 pickets if you use 1x6 dog-ear cedar. Add 10% for waste, cuts, and the occasional board with a crown that won't lay flat. Gate openings add two extra posts (one on each side) and need bracing.
Materials per 100 linear feet by fence style
| Fence style | Posts | Rails | Boards / pickets | Approx material cost |
|---|---|---|---|---|
| 6' wood privacy (8' spacing) | 14 | 28 (2-rail) | 170 pickets | $1,500-$2,500 |
| 6' wood privacy (6' spacing) | 18 | 36 (2-rail) | 170 pickets | $1,700-$2,800 |
| 4' picket fence | 14 | 28 (2-rail) | 115 pickets | $900-$1,500 |
| 3-rail split rail | 14 | 42 rails | None | $600-$1,000 |
| 6' vinyl privacy | 14 | Panels | Panels | $2,500-$4,500 |
| Chain link (6' height) | 14 | 1 top rail | Roll | $1,200-$2,200 |
Material costs only, no installation labor. Add $20-$30 per linear foot for professional installation in most US markets.
Post depth and concrete by fence height
Post depth must be at least one-third of total post length. In cold climates, posts must go below the frost line regardless of this rule:
| Fence height | Post length | Minimum depth | Hole diameter | Concrete per post |
|---|---|---|---|---|
| 3 ft | 5 ft | 18" | 8" | 1 bag (50 lb) |
| 4 ft | 6 ft | 24" | 8" | 1 bag (50 lb) |
| 6 ft | 8 ft | 24-30" | 10" | 2 bags (50 lb) |
| 8 ft | 10 ft | 30-36" | 12" | 2-3 bags (50 lb) |
In northern states, frost lines reach 30-48 inches — always dig below your local frost depth or posts will heave in winter. Corner, end, and gate posts should always be set in concrete. Line posts can be set in compacted gravel and soil if your soil is stable.
Fence calculation formulas
The math behind post, rail, and picket counts:
Rail count = Post count x Rails per span (2 for 6-ft, 3 for 8-ft)
Picket count = Total length (in) / (Picket width + Gap)
Concrete bags = Post count x Bags per post (see table above)
With waste = All material counts x (1 + Waste %)
Standard 1x6 cedar dog-ear pickets are actually 5-1/2" wide. At a 1/8" gap, each picket takes 5.625". For 100 linear feet: (100 x 12) / 5.625 = 214 pickets. For a tight board-on-board privacy style with no gaps, divide linear footage by actual board width.
Fence cost by style (2025 US averages)
| Fence style | Material cost/lin ft | Installed/lin ft | 100 ft total installed |
|---|---|---|---|
| 6-ft cedar privacy | $8-$15 | $20-$40 | $2,000-$4,000 |
| 4-ft wood picket | $5-$10 | $15-$30 | $1,500-$3,000 |
| 3-rail split rail | $4-$9 | $12-$25 | $1,200-$2,500 |
| 6-ft vinyl privacy | $15-$30 | $25-$50 | $2,500-$5,000 |
| 6-ft chain link | $8-$18 | $15-$30 | $1,500-$3,000 |
| Aluminum ornamental | $20-$40 | $30-$60 | $3,000-$6,000 |
Installed cost includes labor, post-hole digging, concrete, and hardware. Gates add $300-$800 each. Northeast and California run 20-35% above these figures. Hillside or rocky terrain adds 15-25% to labor.
Related Calculators
Posts need concrete and wood needs finishing — browse the full construction calculator collection for all related tools.
Frequently Asked Questions
How many fence posts do I need for 200 feet of fencing?
At standard 8-foot spacing: 200 / 8 + 1 = 26 posts. At 6-foot spacing: 200 / 6 + 1 = 35 posts. Always add 1 for the starting end post — the formula calculates spans, not endpoints. Gate openings need two posts each (one per side), which are separate from your line post count.
How deep should fence posts be set?
The rule is one-third of total post length in the ground. A 6-foot privacy fence uses 8-foot posts with 2 feet buried. In cold climates, posts must go below the frost line, which ranges from 12 inches in the South to 48 inches in Minnesota and Canada. Setting posts at frost depth prevents heaving — even a well-concreted post will lift if it's above the freeze zone.
What is the best post spacing for a privacy fence?
8 feet on center is the residential standard for wood privacy fencing. It matches pre-built panel sizes (6x8 and 4x8 panels) and minimizes post count and cost. Use 6-foot spacing in high-wind zones, along hillsides, or for heavier 8-foot tall fences. Closer spacing adds stability but increases post and concrete cost significantly.
How much does it cost to fence a 1/4 acre lot?
A quarter-acre square lot has roughly 417 feet of perimeter. Material-only cost for a 6-foot wood privacy fence runs $6,000-$10,000. Professional installation adds $20-$30 per linear foot — so total installed cost typically falls between $14,000-$22,000 depending on gate count, terrain, and local labor rates.
Can I use metal posts with a wood fence?
Yes — galvanized steel fence posts outlast wood posts by decades and never rot. They are driven or set in concrete the same way, and wood rails attach with special brackets. Metal posts cost more upfront ($15-$25 each vs $8-$15 for treated wood) but eliminate the most common fence failure point. They work especially well in wet climates where ground-contact wood post bases rot quickly even when pressure-treated.