How many bags of mulch do I need?
A 20 x 4 ft flower bed at 3 inches deep takes 10 bags of 2 cu ft. Multiply the bed’s square feet by the depth in inches, divide by 12 for cubic feet, then by the bag size.
The table uses 2 cu ft bags, the most common size. For 3 cu ft bags, multiply the bag count by two thirds.
| Bed | Area | Bags at 2 in | Bags at 3 in | Cubic yards at 3 in |
|---|---|---|---|---|
| 10 x 3 ft | 30 sq ft | 3 bags | 4 bags | 0.28 |
| 20 x 3 ft | 60 sq ft | 5 bags | 8 bags | 0.56 |
| 20 x 4 ft | 80 sq ft | 7 bags | 10 bags | 0.74 |
| 30 x 4 ft | 120 sq ft | 10 bags | 15 bags | 1.11 |
| 50 x 3 ft | 150 sq ft | 13 bags | 19 bags | 1.39 |
| 10 x 10 ft | 100 sq ft | 9 bags | 13 bags | 0.93 |
| 20 x 10 ft | 200 sq ft | 17 bags | 25 bags | 1.85 |
Measuring an odd-shaped bed
Break it into rectangles and add them up. For a round bed, multiply the radius by itself and by 3.14. For a curved border, measure the length along the middle of the curve and multiply by the average width.