Calculators
Post Hole Concrete Calculator
Fence and deck posts are cylinders: π × radius² × depth, times how many holes. Preset: 6 holes, 10 inches diameter, 30 inches deep, 10% waste.
This is the highest-intent concrete query for many DIY projects — do not confuse it with a flat yardage calculator.
Adjust hole count, diameter, and depth in the controls below.
| Item | Area | Size | Buy |
|---|---|---|---|
| Post-hole concrete | — | 9.0 cu ft | 15 bags |
| Ready-mix equivalent | — | 0.3 cu yd | 0.5 cubic yards |
Assumptions
- 6 post holes: 10 in diameter × 30 in deep
- Waste factor: 10%
- Volume: 8.18 cu ft
- Volume with waste: 9.00 cu ft (0.33 cu yd)
- Bag yield: 0.6 cu ft per bag (check bag label)
- Estimates only. Check the coverage figure on your product before buying.
Supplies checklist
- Gravel or crushed stone base
- Wire mesh or rebar (slabs)
- Form boards and stakes
- Concrete mixer or mixing tub
- Float and edger
Estimates only. Check the coverage figure on your product before buying.
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