Worked example: 3 inches deep
| Step | Math | Result |
|---|---|---|
| Area | 5 ft × 10 ft | 50 sq ft |
| Volume at 3 in | 50 × 3 ÷ 12 | 12.5 ft³ |
| Add 5% extra | 12.5 × 1.05 | 13.1 ft³ |
| Cubic yards | 13.1 ÷ 27 | 0.49 yd³ |
| 2 ft³ bags | 13.1 ÷ 2, rounded up | 7 bags |
| 3 ft³ bags | 13.1 ÷ 3, rounded up | 5 bags |
Mulch by depth
| Depth | Cubic feet | Cubic yards (+5%) | 2 ft³ bags | Bag cost | Bulk order (yd³) | Bulk delivered | Cheaper |
|---|---|---|---|---|---|---|---|
| 2 in | 8.3 | 0.32 | 5 | $20 | 1.0 | $115 | Bags |
| 3 in | 12.5 | 0.49 | 7 | $28 | 1.0 | $115 | Bags |
| 4 in | 16.7 | 0.65 | 9 | $36 | 1.0 | $115 | Bags |
At 3 inches, bags win: 7 bags cost about $28 versus $115 for a delivered 1.0 yd³ (which includes a $75 delivery fee).
Prices used: 2 ft³ bag $4, 3 ft³ bag $6; bulk mulch $40/yd³ plus $75 delivery (1 yd³ minimum). Spring sales change the crossover.
Top-ups and depth
If the bed already has mulch, a 1 inch refresh takes only 0.16 yd³ or 3 bags of 2 ft³. Keep mulch 2–3 inches away from trunks and stems.
Nearby sizes
Also see 4×10 bed , 8×8 bed , 4×8 bed, or the mulch by bed size chart. Use the mulch calculator for other sizes.