How do I calculate cubic yards of mulch by area and depth?
Volume = bed area × depth. Bags = volume ÷ labeled bag volume, rounded up.
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Mulch calculator
Estimate mulch volume and purchase quantity from bed shape, dimensions, and depth.
- Metric and imperial units
- Instant updates as inputs change
- Data is calculated in this browser only
Results are planning estimates. Confirm site dimensions, product specifications, and installation waste before purchasing.
Preparing calculator…
Calculation notes
Understand the Mulch calculator
Area from each selected shape is multiplied by depth to get volume. Total volume is divided by bag yield and rounded up, with cubic-foot, cubic-yard, and cubic-meter conversions.
How many bags cover a 12 by 6 ft bed at 3 in deep?
A 12 × 6 ft bed at 3 in deep needs 18 cu ft, or about 0.67 cu yd. With 2 cu ft bags, buy 9 bags before any extra allowance.
Should mulch depth use loose or finished material height?
- Compare the calculated cubic yards with local bulk-delivery minimums.
- Use finished depth, not the loose pile height.
What site conditions can change the amount of mulch needed?
- Settlement and uneven grade can change actual volume.
- For larger jobs, compare bags with bulk delivery.
- Settlement, existing mulch, slopes, and irregular edges affect delivered volume.
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