Garden & Outdoor
Fence Calculator
Enter your fence length, style, and post spacing to get an exact material list — posts, rails, pickets, and concrete bags included.
Calculate Fence Materials
Measure all sides of your fence perimeter that need fencing.
How the Fence Calculator Works
The calculator divides your total fence length by your post spacing to find the number of sections, then computes posts, rails, and pickets from that section count. Gate openings subtract pickets but keep their posts.
The Formulas
- Sections = total length (ft) ÷ post spacing (ft), rounded up
- Posts = sections + 1, plus 1 extra per gate opening
- Rails = sections × rails per section
- Pickets = fenced sections × ⌈(post spacing × 12) ÷ (picket width + gap)⌉
- Buy quantity = pickets × 1.10 (10% waste buffer), rounded up
- Concrete = posts × 1.5 bags, rounded up (2 bags for gate/corner posts)
Pickets Per Section by Size
| Picket | Face Width | Gap | Per 6 ft section | Per 8 ft section |
|---|---|---|---|---|
| 1×4 (tight) | 3.5" | 0" | 21 pickets | 28 pickets |
| 1×6 (tight) | 5.5" | 0" | 14 pickets | 18 pickets |
| 1×6 (shadow-box) | 5.5" | 1/4" | 13 pickets | 17 pickets |
Counts are before the 10% waste factor.
Worked Examples
Example 1: Backyard Privacy Fence
Length: 120 linear ft
Style: Privacy, 1×6 pickets
Spacing: 6 ft posts, 3 rails, 1 gate (4 ft)
Sections: 120 ÷ 6 = 20 sections
Posts: 20 + 1 + 1 gate = 22 posts
Rails: 20 × 3 = 60 rails
Fenced sections: (120 − 4) ÷ 6 = 20 sections
Pickets: 20 × 14 = 280 → +10% = 308 pickets
Concrete: 22 × 1.5 = 33 bags
Example 2: Split Rail Side Yard
Length: 60 linear ft
Style: Split rail (no pickets)
Spacing: 8 ft posts, 2 rails
Sections: 60 ÷ 8 = 7.5 → 8 sections
Posts: 8 + 1 = 9 posts
Rails: 8 × 2 = 16 rails
Concrete: 9 × 1.5 = 14 bags
Example 3: Dog Run Perimeter
Length: 80 linear ft
Style: Privacy, 1×4 pickets
Spacing: 6 ft posts, 3 rails, 2 gates (3 ft each)
Sections: 80 ÷ 6 = 13.3 → 14 sections
Posts: 14 + 1 + 2 gates = 17 posts
Rails: 14 × 3 = 42 rails
Fenced run: 80 − 6 = 74 ft → 13 sections
Pickets: 13 × 21 = 273 → +10% = 301 pickets
Pro Tips
Expert advice to get better results on your project.
Mark post locations before you dig
Run a string line along the full fence run first, then mark post centers with spray paint or stakes. This catches alignment problems before you've dug 14 holes. A 3-4-5 triangle check at each corner ensures your fence will be square to the house or property line.
Add gravel under every post
Put 6 inches of gravel at the bottom of each post hole before setting the post. It lets water drain instead of pooling around the post base — the #1 cause of premature rot in pressure-treated posts. Tamp it firm before you set the post.
Use fast-set concrete, not regular mix
Quikrete Fast-Setting Concrete lets you set posts and hang rails the same day — no 24-hour wait. Pour the dry mix into the hole, add water on top, and it's solid in 20–40 minutes. Only advantage of regular mix: it's cheaper per bag for very large jobs.
Pre-drill pickets before nailing
Nailing pickets without pre-drilling causes splitting, especially near board ends. A quick 1/8-inch pilot hole takes seconds and results in a cleaner install. If you're using a nail gun, angle the nails slightly toward each other for better pull-out resistance.
Use a spacer for consistent picket gaps
Cut a scrap piece of wood to your desired gap width (zero for privacy, 1/4-inch for a shadow-box look). Drop it between each picket as you nail — it takes two seconds and ensures perfectly uniform spacing down the entire run.
Cap your posts to prevent rot
End grain on top of posts soaks up water like a sponge and rots from the inside out. Install a plastic or metal post cap on every post — they're inexpensive and extend post life by years. If you don't use caps, cut a slight angle (15°) on top so water sheds off.
Ready to Buy Fence Materials?
Posts, pickets, concrete, and tools from trusted retailers.
Quikrete Fast-Setting Concrete Mix — 50 lb
No mixing required — pour dry into the hole, add water on top, and posts are set solid in 20–40 minutes. One bag sets a typical 4×4 line post. Corner and gate posts need two bags.
~$8/bag
Southland 4×4×8 Pressure-Treated Fence Post
Standard #2 pressure-treated pine post for 6-foot privacy fences. Ground contact rated (UC4B treatment). For 8-ft fences use 4×4×12. Check local box stores for in-stock lengths.
~$13–$18/post
Vigoro 1×6×6 Dog-Ear Pressure-Treated Privacy Fence Picket
The most common privacy fence picket. Dog-ear top sheds water. Pressure-treated for ground contact. Available in both 1×4 and 1×6 widths — 1×6 fills faster and uses fewer fasteners.
~$3–$5/picket
Milwaukee M18 Cordless Drill/Driver — 2-Tool Combo Kit
Drill pilot holes and drive screws all day on one charge. The combo kit includes both a drill and an impact driver — use the drill for pilot holes, impact driver for screws. Essential for any fence project.
~$199
YARDGARD 2×4×8 Pressure-Treated Fence Rail
Standard horizontal rail for privacy and picket fences. Two rails per section for fences under 5 ft, three rails for 6 ft and above. Notch into post or use a fence rail bracket for a faster install.
~$8–$12/rail
Simpson Strong-Tie Post Cap — 4×4 (pkg of 10)
Galvanized metal post caps keep water off end grain and dramatically extend post life. Takes 30 seconds per post to install. Inexpensive insurance against the #1 cause of fence post rot.
~$18/10-pack
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Frequently Asked Questions
Common questions about planning and estimating fence materials.