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Calculate the number of fence posts, concrete bags, and materials needed. Includes post depth, spacing, and hole size calculations.
Each gate adds 2 extra posts
Pre-mix concrete, pour wet - best strength
| Fence Height | Minimum Depth | Recommended | Post Length |
|---|---|---|---|
| 3-4 ft | 18" | 24" | 6 ft |
| 6 ft ★ | 24" | 30" | 8 ft |
| 8 ft | 30" | 36" | 10 ft |
Rule of Thumb: Bury 1/3 of the total post length, or at minimum, bury the post 2 feet deep. In cold climates, dig below the frost line to prevent heaving.
| Post Size | Minimum Hole | Recommended | Notes |
|---|---|---|---|
| 4×4 ★ | 8" | 10" | 3× post width is ideal |
| 6×6 | 10" | 12" | For gates, corners |
Hole diameter should be approximately 3× the post width to allow proper concrete coverage around all sides.
Pour dry mix, add water - quick but less strong
Pre-mix concrete, pour wet - best strength
More concrete for large posts or soft soil
Good drainage, allows future removal
Posts = (Fence Length ÷ Spacing) + 1 + (Gates × 2)Always round up, add 2 posts per gate
Volume = π × r² × depthWhere r = hole radius in feet, depth in feet
Concrete = Hole Volume - Post VolumeSubtract the post displacement from total hole volume
Bags = Concrete Volume ÷ 0.45 (60lb bag yield)60lb bag yields ~0.45 cu ft, 80lb yields ~0.60 cu ft