Math: 27 ÷ 0.6 = 45 bags. Add 5-10% waste → 48-50 bags. 60-lb bags: 27 ÷ 0.45 = 60, buy 63-66.
| Project | Volume | 80-lb bags |
|---|---|---|
| 10×10ft, 4in | 13.3 cu ft (0.49 yd) | 23 buy 25 |
| 10×10ft, 3in | 25 cu ft (0.93 yd) | 42 buy 45 |
Sources: retailer calculators + 0.6/0.45 yields. Estimates only.