Order of work
- Check the property line and permits. Many towns limit fence height (often 4 ft in front yards, 6 ft behind) and require a permit. Call 811 (in the US) a few days before digging to have utilities marked.
- Lay out the line with stakes and string. Mark the corner and gate posts first, then mark line posts at the spacing shown.
- Dig the holes to the depth shown above — a power auger (rentable) saves hours on long fences.
- Pour 6 in of gravel into each hole and tamp it for drainage.
- Set corner and gate posts first, plumb them in two directions and brace them. Pour fast-setting concrete per the bag directions and crown the top so water runs off.
- Run a string between corner posts at the finished height and set the line posts to it.
- Attach the rails once the concrete has cured (see the bag), then fasten the pickets with two screws per rail, using a spacer block for even gaps.
- Hang the gates with the hardware kit, leaving about ½ in clearance on the latch side, then cut the post tops and add caps.
Tools you’ll need
- Post hole digger or rented power auger
- Tape measure, stakes, mason’s line and line level
- 4 ft level or post level, and scrap 2×4s for bracing
- Circular saw or miter saw
- Drill/driver and an impact driver for screws
- Wheelbarrow, shovel and tamping bar
- Safety glasses, gloves and hearing protection
About this planner
A wood fence is posts set in concrete, horizontal rails between them and pickets across the face — plus the parts people forget until they're at the checkout: drainage gravel under every post, the right post length for the fence height, enough screws, and hardware for each gate. This planner works out all of it from your fence line, height, style and gates, prices every line, and draws the layout and one section to scale so you can see exactly what you're building.
It follows common residential practice: posts buried a third of the fence height (at least 2 ft) on 6 in of gravel, holes about three times the post width, and three rails for a 6 ft privacy fence.
How to use it
- Measure the total length of every straight run, including gate openings, and add them up.
- Choose the height, style and post spacing. 8 ft spacing matches standard 8 ft rails.
- Enter the number of gates, their width and the number of corners where the fence turns.
- Open Your local prices, enter your supplier’s prices, then print the project sheet.
How the quantities are worked out
Sections = (fence length − gate openings) ÷ post spacing, rounded up
Posts = sections + 1 + gates + corners
Post length = fence height + burial depth (⅓ of height, at least 2 ft), rounded up to 6/8/10/12 ft stock
Rails = sections × rails per section (2 up to 4 ft, 3 for 6 ft, 4 for 8 ft)
Pickets = fence length ÷ (picket width + gap) × 1.05
Concrete per post = (π × (hole ÷ 2)² − post area) × burial depth, in 50 lb fast-setting bags (0.375 cu ft each)
Gravel per post = π × (hole ÷ 2)² × 6 in, in 0.5 cu ft bags
Holes are about three times the post width: 10 in for a 4×4 (actual 3.5 in square), 16 in for a 6×6. A 4×4 set 2 ft deep in a 10 in hole takes about 0.92 cubic feet of concrete — two and a half 50 lb bags of fast-setting mix. The layout drawing straightens the fence line; corners are counted in the post total but not drawn.
Worked example
These are the planner’s starting values and the results they produce:
| Total fence length | 100 ft |
|---|---|
| Fence height | 6 ft (standard privacy) |
| Style | Privacy (pickets butted tight) |
| Post spacing | 8 ft on center (standard) |
| Gates | 1 |
| Gate width | 4 ft |
| Corners | 2 |
| Post size | 4×4 (most fences up to 6 ft) |
| Post, each | $18.00 |
| 2×4 rail, each | $9.00 |
| Picket, each | $3.50 |
| Fast-setting concrete, per 50 lb bag | $7.00 |
| Gravel, per 50 lb bag | $5.50 |
| Gate hardware kit, each | $35.00 |
| Bought | Item | Buy | Cost |
|---|---|---|---|
| Posts, 4×4 pressure-treated (ground contact)12 sections + 1 gate post + 2 corner posts | 16 × 8 ft | $288.00 | |
| Rails, 2×4 × 8 ft3 per section | 36 | $324.00 | |
| Pickets, 1×6 × 6 ftbutted tight, incl. gates and 5% spare | 230 | $805.00 | |
| Fast-setting concrete, 50 lb2.5 per post in 10 in holes | 40 bags | $280.00 | |
| Drainage gravel, 50 lb6 in under each post | 9 bags | $49.50 | |
| Exterior screws, 2 in2 per picket per rail | 1,400 | — | |
| Gate hardware kit (hinges + latch)4' opening | 1 | $35.00 | |
| Estimated materials total | $1,781.50 |
Tips before you buy
- Use posts rated for ground contact, even if the pickets are cedar — they’re the part that rots.
- Buy rails and pickets from the same stack and check them for twist; return badly warped boards.
- Gates longer than 4 ft sag; use a 6×6 gate post or a heavy-duty anti-sag kit.
- Order a few extra pickets and one spare post — splits and bad cuts happen.
- Wait until the concrete has cured before hanging rails or gates; fast-setting mix sets quickly but gains strength over days.
Frequently asked questions
How many posts do I need for a 100 ft fence?
With posts every 8 ft, a 100 ft fence with one 4 ft gate and two corners needs 16 posts: 12 sections plus 1 end post, 1 gate post and 2 corner posts.
How much does a 100 ft wood privacy fence cost in materials?
With typical prices — $18 posts, $9 rails, $3.50 pickets and $7 bags of fast-setting concrete — a 100 ft, 6 ft tall privacy fence with one gate comes to about $1,780 in materials, or roughly $18 per foot. Pickets are the largest cost.
How deep should fence posts be?
Bury about a third of the fence’s height, and at least 2 ft: 2 ft for 4 and 6 ft fences, about 2 ft 8 in for an 8 ft fence. In cold climates, go below the frost line; check local requirements.
How long should posts be for a 6 ft fence?
Six feet above ground plus two feet buried is 8 ft, so buy 8 ft posts. An 8 ft fence needs about 10 ft 8 in of post, which means 12 ft stock.