Count posts by type, not by total. Then add concrete by the bag, fasteners by the coating, and gate hardware by the leaf weight — those three lines decide whether the fence is still straight in five years.
Numbers to plan with
Convert the layout into saleable units
A fence is sold as posts, panels or pickets, rails, concrete, and hardware, while it is measured in linear feet. Bridge the two with bay count. For a 100 ft (30.5 m) run at 8 ft (2.4 m) bays, 100 ÷ 8 = 12.5, so build 13 bays at 7.69 ft (2.34 m): 14 posts and 13 panels. Rounding to 12 bays would push spacing to 8.33 ft and overrun the panel system.
For a picket-built fence, the panel is assembled on site, so the picket count comes from panel width and picket width. An 8 ft panel using 5.5 in (140 mm) pickets with 0.5 in gaps fits 16 pickets: 16 × 5.5 = 88 in plus 15 gaps at 0.5 in = 95.5 in, inside the 96 in panel. Multiply by 13 bays and you need 208 pickets, plus 10 to 15 spares for knots, splits, and the inevitable mismeasurement.
Buy the gate as a unit or build it from a kit, but count it separately from the panel run. A gate replaces one panel and adds two posts, hinges, a latch, and often a drop rod. On the material list, the gate should never be a line item called 'gate hardware' with no quantity attached.
- Panels = bays. Posts = bays + 1 per open run, plus one per gate post.
- Pickets per panel = floor((panel width − 0.5 in) ÷ (picket width + gap)) + 1.
- Add 5 percent spare pickets and one spare panel; matching stock disappears from shelves fast.
A material list for 100 ft of 6 ft wood privacy fence
The quantities below describe a 6 ft (1.8 m) dog-ear privacy fence with three rails per bay, 13 bays at 7.69 ft, and one 4 ft gate. Treat it as a template: substitute your actual bay count and panel dimensions, then adjust the rail count if your design uses two rails on a 4 ft fence.
Concrete is calculated at 3 bags of 80 lb mix per line post and 4 bags per gate post, with a 12 in hole at 36 in deep for the gates. Fastener quantities assume two fasteners per rail end and hidden fasteners for pickets; clip-based systems use a different count, so read the bucket label.
Shopping list template for 100 ft of 6 ft wood privacy fence
| Item | Quantity | Unit | Why this number |
|---|---|---|---|
| 4x4x8 posts | 14 | each | 13 bays plus one end; gate posts upgraded separately |
| 6 ft dog-ear pickets | 208 + 12 spare | each | 16 per panel across 13 panels |
| 2x4x8 rails | 39 | each | Three rails per bay for a 6 ft fence |
| 80 lb concrete mix | 44 | bags | 3 per line post, 4 per gate post |
| 2-1/2 in exterior screws | 6 | lb | Rails, pickets, and gate frame |
| Hot-dip galvanized brackets | 26 | each | Two per rail end at posts |
| 4 ft gate kit | 1 | kit | Frame, hinges, latch, and stop |
| Post caps | 14 | each | Optional, but they shed water off end grain |
Posts are not one SKU
A fence needs line posts, corner posts, end posts, and gate posts, and they are not interchangeable. Line posts carry rails from one direction. Corner posts carry two runs at 90 degrees and should be a size up — 5x5 or 6x6 on a 6 ft privacy fence. End posts carry one run with nothing balancing the pull, so they need a brace or a deeper footing. Gate posts carry a moving leaf and should be the heaviest post on the job.
Wood posts are sold as 4x4, 5x5, and 6x6 nominal, which measure 3.5, 4.5, and 5.5 in actual. Ground-contact rated lumber is marked for the application; a post rated for above-ground use will rot at the soil line even if the concrete is crowned perfectly. For steel, chain link line posts are commonly 1-5/8 or 2-3/8 in pipe, while terminal posts run 2-7/8 in or larger; the gauge and coating matter as much as the diameter.
Order posts 6 to 12 in longer than the finished height above grade plus the buried depth. A 6 ft fence with 30 in of embedment needs an 8 ft post with a few inches of trim, not an 8 ft post cut to 5 ft 6 in because the concrete came up high.
Concrete, gravel, and the footing arithmetic
Ready-mix bags are sold by weight, not volume, and the yield printed on the bag is the number that matters. An 80 lb bag yields about 0.6 cu ft (17 L); a 50 lb bag yields about 0.375 cu ft (10.6 L). A 10 in by 30 in hole is 1.36 cu ft, so it takes 2.3 bags of 80 lb mix. Buy 3 and keep the surplus for the next post rather than opening a fourth bag to top off a sloppy hole.
Mix to a stiff, moldable consistency — roughly 3 to 3.5 qt of water per 80 lb bag, following the bag instructions. Too much water weakens the mix and increases shrinkage, which is how a post ends up loose in a hole that looked full. Set the post, check plumb in two directions, and brace it with two stakes and a scrap rail until the concrete sets. Do not backfill with soil on top of a partial pour; the soil layer holds water against the post.
Cure time matters more than most crews allow. Concrete reaches useful strength in about 24 hours and most of its design strength in 7 days. Hanging a gate and tensioning a long run on the same day is a common cause of posts that lean 2 degrees by the end of the season. Set posts on day one, build panels on day two, and hang gates last.
- Gravel: 4 to 6 in (100 to 150 mm) at the bottom of each hole for drainage.
- Crown: slope concrete away from the post, 1/4 in per 12 in of radius.
- Bracing: two stakes per post until the concrete reaches 24 hours of cure.
Hardware fails before lumber does
Modern pressure-treated lumber is commonly treated with copper-based preservatives, and the copper attacks zinc coatings. Electro-galvanized nails and screws can show rust in two to four years in a fence, while hot-dip galvanized or stainless fasteners last the life of the wood. In coastal zones within about 1,000 ft (300 m) of salt water, specify stainless for everything exposed, including hinges and latches.
Hinges are rated by leaf weight and width, not by gate height. Three 4 in hinges handle a 4 ft wood gate; a 6 ft gate needs four hinges plus an anti-sag truss or a diagonal brace. Through-bolt the hinge leaves instead of using lag screws, and use a latch with a positive stop so the gate does not rely on the latch bolt to hold it square.
Every metal-to-wood contact is a corrosion cell waiting for water. Use brackets and caps that are rated for treated lumber, and isolate aluminum components from direct contact with copper-treated wood. A $12 bag of stainless screws is cheaper than replacing 40 ft of pickets that stained black from fastener corrosion.
Finish, delivery, and the permit sequence
New pressure-treated wood needs 30 to 60 days of drying before stain, and a bead-of-water test tells you when: if water beads on the surface, the wood is still too wet to absorb finish. Cedar can take a penetrating oil after 2 to 4 weeks. Paint on galvanized steel needs a weathered or etched surface, or the coating will fail in sheets. Composite and vinyl need no finish, but they do need a wash with mild soap once a year to keep mildew off the north face.
Sequence the paperwork before the delivery. The 811 locate request takes a few business days, a fence permit commonly takes 5 to 20 business days depending on the jurisdiction, and HOA architectural review can take 2 to 6 weeks. Ordering material before the HOA approves a height or style is how homeowners end up with 14 posts they cannot set.
On delivery day, confirm truck access. A 12 ft gate and a 60 ft driveway are enough for most flatbed drops, but a 10 ft opening with a low wire overhead is not. Stack pickets and panels on 4x4 sleepers, not directly on grass, and keep them covered at the top only — wrapping the whole stack traps moisture and invites mold. Stage material within 20 ft (6 m) of the fence line if the ground allows; every extra 100 ft of carry adds roughly 10 to 15 minutes per trip for two people.
- Confirm the return policy on special-order panels and custom gates before you buy extras.
- Keep 5 to 10 percent spare pickets and one spare post for storm and vehicle damage.
- Photograph the delivered material before installation for warranty and damage claims.
Questions that come up on this job
How many pickets do I need for 100 ft of 6 ft fence?
About 208 pickets plus 12 spares for 13 bays at 16 pickets per 8 ft panel. The exact count depends on picket width and gap: wider pickets or tighter gaps reduce the count per panel, and a 7.69 ft bay may fit 15 rather than 16.
Can I use regular deck screws for a treated wood fence?
Use fasteners rated for treated lumber, preferably hot-dip galvanized or stainless. Standard electro-galvanized or interior screws corrode quickly in copper-treated wood, and the rust stains bleed down the pickets within a few seasons.
Should I set posts in concrete or gravel?
Concrete is the default for gate, corner, and end posts because it resists lateral load. Gravel or compacted aggregate can work for light line posts in well-drained soil, but it offers less resistance to frost heave and wind, and it is not accepted by every inspector.
How long should I wait before staining a new wood fence?
Wait 30 to 60 days for pressure-treated lumber and 2 to 4 weeks for cedar, then test with a splash of water. If the water beads, the wood is still too wet; if it soaks in, the surface is ready for a penetrating stain.
Sources & further reading
References behind this guide
These sources support the safety, measurement, or industry conventions used above. Product instructions, approved plans, and local requirements control your project.