Short answer
An 80-foot dog run fence requires 160 pickets using 5.5-inch-wide boards with a 0.5-inch gap between them. You'll also need 11 posts, 10 rails, and 22 bags of 60 lb concrete to complete the job.
How this calculator works
The picket count comes from one straightforward formula: convert your fence length to inches, then divide by the combined width of one picket plus one gap, and round up to the nearest whole picket.
For this 80-foot run:
- 80 feet × 12 = 960 inches of fence
- Picket width (5.5 in) + gap (0.5 in) = 6 inches per picket slot
- 960 ÷ 6 = 160 pickets exactly
No rounding was needed here because 960 divides evenly by 6. In most real projects, you get a fractional result and the calculator rounds up—you always need a full picket to fill even a partial slot.
The gap input matters more than most people expect
Changing the gap from 0.5 in to 1 in on this same 80-foot run drops the count to 147 pickets. Going to a true privacy fence with 0-inch gaps raises it to 175. The gap field is not decorative—run the numbers before you order.
Secondary outputs explained
Posts: The formula places a post every 8 feet and adds one for the far endpoint: ceil(80 / 8) + 1 = 11. Eight-foot spacing is the standard for 2×4 rails; go to 6-foot spacing if you're in a high-wind zone or using heavy cedar pickets.
Rails: The calculator assumes two horizontal rails (top and bottom) and 16-foot stock. ceil((80 × 2) / 16) = 10 rails. If you're building taller than 5 feet, add a third center rail and recalculate: ceil((80 × 3) / 16) = 15 rails.
Concrete: Two 60 lb bags per post hole, so 11 posts × 2 = 22 bags. That's enough concrete volume to fill a typical hole that's 10 inches in diameter and 24 inches deep. In cold climates where the frost line runs deeper, you may need a third bag per post.
Linear feet of pickets: The output shows 80.0 linear feet. That's the total fence coverage the pickets actually span—in this case it matches the fence length exactly because the math worked out evenly. Use this number if your lumber yard prices cedar by the linear foot rather than by the piece.
What the calculator does not include
- Gates: Each gate opening removes pickets and adds hardware. Subtract the gate width from your fence length before calculating, then add gate kit materials separately.
- Grade changes: A sloped yard requires racking or stepping the fence. Both methods alter how pickets line up and can increase waste. Add 10–15% to your picket count on slopes steeper than 2 inches of rise per 8-foot section.
- Waste factor: The base formula gives you the theoretical minimum. The default 5% waste factor means ordering 168 pickets instead of 160. For a first-time install, 10% is more realistic.
Checking your own numbers
If you change any input—say, your dog run is actually 83 feet, or you want 1-inch gaps for airflow—re-enter those values and the calculator recomputes instantly. The formula stays the same; only the inputs change.
Recommended materials
Cedar is the standard choice for dog runs because it doesn't need a chemical treatment to resist rot, and it weathers to a clean gray if left unfinished. Pair it with pressure-treated posts and rails, which are in ground contact and need the extra protection. Set posts with fast-setting concrete—you can backfill and move on without waiting for a full cure.
- Cedar dog-ear picket 5/8 in x 5-1/2 in x 6 ft
- Pressure-treated 4x4 in x 8 ft fence post
- Pressure-treated 2x4 in x 16 ft fence rail
- Quikrete fast-setting concrete (60 lb bag)
FAQ
How many fence pickets do I need for an 80-foot dog run? You need 160 pickets when using standard 5.5-inch-wide boards with a 0.5-inch gap. That accounts for the full 80 linear feet with no waste factor added. Buy an extra 5–10% to cover splits and cut waste.
How many fence posts does an 80-foot run require? At 8-foot spacing with one post at each end, you need 11 posts. Space them evenly and set them at least 2 feet deep—deeper in frost-prone areas.
How many rails do I need for 80 feet of fence? Using 16-foot pressure-treated 2x4 stock with two rails per bay (top and bottom), you need 10 rails. Add a third middle rail if your pickets are taller than 5 feet.
How many bags of concrete do I need to set 11 fence posts? Plan on 2 bags of 60 lb concrete per post hole, so 22 bags total. Fast-setting concrete works well for fence posts—no mixing required, just pour dry and add water.
What is the standard gap between privacy fence pickets? A 0.5-inch gap is the most common choice for privacy fences. It allows slight expansion and contraction of wood with humidity changes without leaving visible openings.
Does a dog run fence need a different spacing than a standard privacy fence? For small or determined dogs, close the gap to 0 inches or use a solid board-on-board pattern where pickets overlap slightly. A 0.5-inch gap is fine for most medium and large dogs.
Should I add a waste factor when buying pickets? Yes. Add at least 5% to the base count—that is 8 extra pickets on a 160-picket order. For rough-cut cedar with variable widths, 10% is safer.
What picket height should I use for a dog run? Most dog owners use 6-foot pickets. For large breeds that jump or climb, consider 8-foot pickets and adjust post height accordingly.
Is cedar or pressure-treated wood better for a dog run fence? Cedar is naturally rot-resistant and safe for pets. Pressure-treated lumber is more durable long-term but older formulations contained arsenic—modern ACQ-treated wood is considered safe, though some owners prefer cedar for direct animal contact areas.
How do I calculate pickets if my fence length is not a round number? Divide your total length in inches by the sum of picket width plus gap, then round up to the nearest whole number. For any fraction of a picket space, you need one full picket.
Can I use the same formula for a board-on-board fence? No. Board-on-board fences overlap each picket by 1–2 inches, so you need roughly 20–30% more pickets. Adjust the effective picket width in the calculator to account for the overlap.
What fasteners do I need for 160 pickets? Each picket typically gets two fasteners per rail, so 4 screws or nails per picket on a two-rail fence—640 fasteners total. Buy a box of at least 1 lb of 1.5-inch exterior screws or hot-dipped galvanized nails.