Worked example: a 64 ft picket fence
Hypothetical educational example. Posts, rails, pickets and post-hole concrete come from the fence calculator. The 30 inch hole depth is a scenario assumption, not a local frost depth and not a code embedment.
Inputs
| Run | 64 ft |
|---|---|
| Post spacing | 8 ft |
| Gates | 1 × 4 ft |
| Rails per section | 3 |
| Pickets | 5.5 in wide, no gap |
| Picket waste | 5% |
| Hole | 10 in diameter, 30 in deep, 3.5 in post |
| Concrete | 80 lb bags, plus the calculator’s own 10% on each hole |
Arithmetic
- Infill = 64 − 4 = 60 ft. Sections = ceil(60 ÷ 8) = 8. Posts = 8 + 1 + 1 gate = 10.
- Pickets = ceil(60 × 12 ÷ 5.5) = 131, then × 1.05 = 137.55, which rounds up to 138.
- Rails = 8 × 3 × 1.05 = 25.2, which rounds up to 26.
- One hole is about 1.15 cu ft. With the built-in 10% and a 0.60 cu ft bag, that is 3 bags per post, 30 bags in total.
Required, waste and purchase
- Required
- 137.55 pickets before the final roundup, 25.2 rails, and 2.11 bags of concrete per hole before that quantity rounds up.
- Purchased
- 10 posts, 26 rails, 138 pickets and 30 × 80 lb bags (3 per post). Pickets are counted as pieces, not as a pack with a manufacturer piece count.
- Units
- US feet and inches, and 80 lb bags at 0.60 cu ft.
Assumptions
- Hole depth and diameter are scenario inputs. They are not a frost-line recommendation.
- The 10% on concrete is inside the fence calculator and is separate from the 5% picket waste.
What this example does not decide
- Not a wind design, a height limit, or a gate-leaf design. The result counts one gate kit.
- There is no separate fencing topic. The category page remains the tool list.
Where to go next
- Fence calculator — Run these inputs
- Fencing calculators — Tool list
- Fence planning checklist — What to decide before the count
- Stain calculator — Finish after the fence is up
Questions
Is 30 inches the right hole depth?
Not as a rule. It is the number this example typed. Local frost depth and fence height can require something else. The calculator will count bags for the depth you enter. It will not choose the depth.
Why is there no fencing topic page?
One calculator already returns posts, rails, pickets and concrete. A topic hub beside the category page, the guide and the calculator would repeat the same post-spacing formula. This example links those three pages instead.
Sources
- Quikrete – Concrete Mix (No. 1101) product data sheet — accessed 2026-10-19: “An 80 lb (36.2 kg) bag yields approximately 0.60 ft³ (17 L).”