How it works
Sections = fence length (minus gates) ÷ post spacing, rounded up. Posts = sections + 1, plus one for each corner and gate. For board fences, pickets = fence length ÷ (picket width + gap). Concrete is the volume of each hole minus the post, times the number of posts.
| Item | Typical |
|---|---|
| Post spacing | 6–8 ft (1.8–2.4 m) |
| Hole diameter | About 3× the post width (10–12" for 4×4) |
| Hole depth | About ⅓ of the post height above ground, 24" (600 mm) minimum, below the frost line |
| Rails per section | 2 for fences up to about 4 ft, 3 for 5–6 ft |
Before you dig
- Call or book a utility locate before you dig (811 in the US), to avoid buried cables and pipes.
- Check your property line, local height limits and any HOA rules.
- Buy a spare post and a few spare pickets for splits and mistakes.
Step-by-step: how to calculate fence materials. For a slab or footings, use the concrete calculator.
FAQ
How far apart should fence posts be?
Usually 6–8 ft (1.8–2.4 m) for wood fences. Ready-made panels set the spacing: 8 ft panels in the US, 6 ft (1.83 m) panels in the UK. Closer spacing is stronger in windy or exposed spots.
How deep should a fence post hole be?
A common rule is about one-third of the post’s height above ground, and at least 24 in (600 mm), deeper in frost-prone areas so the post sits below the frost line. Check local guidance.
How wide should a post hole be?
About three times the post width: roughly 10–12 in for a 4×4 post and 12–16 in for a 6×6.
How many bags of concrete per fence post?
For a 4×4 post in a 10 in × 30 in hole, about 1.4 cu ft, which is roughly four 50 lb bags of fast-setting mix or two to three 80 lb bags of standard mix. Use the calculator for your hole size.