How much mulch covers your garden bed?
Measure the bed’s length and width, then choose the depth of the new mulch layer. For several separate beds, calculate each rectangle and combine their unrounded volumes before rounding a bulk order. Do not count overlapping areas twice.
Required volume = net volume × (1 + allowance ÷ 100)
Bags = ceil(required volume ÷ bag volume)
Bulk order (yd³) = required volume ÷ 27, rounded up to 0.1 yd³
Bag size is entered as volume, not weight. A 2 ft³ bag covers 12 ft² at 2 inches deep, 8 ft² at 3 inches, or 6 ft² at 4 inches. These are volume-based estimates; spreading evenly and measuring the bed determine actual coverage.
Worked example: a 12 × 8 ft bed
The bed covers 96 ft². A new 3-inch layer requires 24 ft³, with no additional allowance. That is 12 bags of 2 ft³, or about 0.89 yd³ before rounding to a 0.9 yd³ bulk estimate. At an example $4 per bag, the bagged material costs $48. At an example $40 per yd³, the rounded bulk estimate costs $36 before delivery.
Choosing bags or a bulk load
For smaller beds, bags make it easier to move mulch to individual planting areas. At 1 yd³ or 20 bags and above, this tool recommends comparing bulk delivery. These are planning thresholds, not proof that one option is cheaper. Delivery fees and supplier minimums can change the decision.
If topping up existing mulch, enter only the new layer needed. Check your mulch product’s application directions and the existing layer before choosing depth. Keep mulch clear of plant stems and tree trunks. The calculator estimates material only, excluding delivery, spreading, bed preparation and tax.
Product reference: Scotts Nature Scapes 2 ft³ mulch is one example of volume-based bag packaging; other products may use different bag sizes.