Calculator + chartEnter your measurements below and it works the answer out.
A cubic yard of mulch covers 108 sq ft at 3 in deep. Enter your area and depth for the volume, the weight range and the bag count, with 5% waste added.
| Depth | Square feet covered | Square feet per cubic foot |
|---|---|---|
| 1 in | 324 sq ft | 12 sq ft |
| 2 in | 162 sq ft | 6 sq ft |
| 3 in | 108 sq ft | 4 sq ft |
| 4 in | 81 sq ft | 3 sq ft |
| 5 in | 64.8 sq ft | 2.4 sq ft |
| 6 in | 54 sq ft | 2 sq ft |
| 8 in | 40.5 sq ft | 1.5 sq ft |
| 12 in | 27 sq ft | 1 sq ft |
Every figure here is 324 ÷ depth in inches, because a cubic yard is 27 cubic feet and one square foot at D inches deep is D/12 of a cubic foot. Nothing on this site uses a coverage number that does not come out of that line.
The rule. A cubic yard is 27 cubic feet. Spread D inches deep it covers 324 ÷ D square feet — so a cubic yard of mulch 2 in deep covers 162 sq ft, 3 in deep covers 108 sq ft, 4 in deep covers 81 sq ft. Multiply your area by the depth in feet, divide by 27, and that is your order in cubic yards. Everything else on this page is that line with the units changed.
Depth is the decision, not the area. Three inches is the working depth: enough to suppress weeds and hold moisture, not so much that it smothers roots. Two inches is a refresh over existing mulch. More than four inches around a trunk causes rot rather than preventing it.
How it is sold. Bulk mulch is sold by the cubic yard. Bagged mulch is sold in 2 cubic foot bags, and 13.5 of them make a yard.
Weight is a range, and deliberately so. Mulch runs about 0.4 to 0.8 tons per cubic yard. That is a real spread, not sloppiness: bulk material weighs more wet than dry, and more when it is fine than when it is coarse. Order by volume, and use the tonnage only to check that a delivery ticket is in the right country.
Waste. This calculator adds 5%. Ground is never as flat as a tape says it is, edges are never square, and running out halfway through means a second delivery charge for a fraction of a load. 5% is the allowance that stops that without leaving a pile you have to get rid of.
Multiply the area in square feet by the depth in feet, then divide by 27 for cubic yards. A 10 by 12 ft area at 3 in is 1.11 cubic yards before waste. The calculator above does it and adds the 5% allowance.
At 2 in it covers 162 sq ft. At 3 in it covers 108 sq ft. At 4 in it covers 81 sq ft. The figure is always 324 divided by the depth in inches.
About 0.4 to 0.8 tons per cubic yard. The range is real — moisture and grading move it — so treat the middle of it as an estimate and never as a delivery spec.
13.5 bags, because a cubic yard is 27 cubic feet and the standard bag holds 2. That is worth knowing before you load a trolley — nine bags is two thirds of a yard and about as much as a car will take.
Three inches over open soil, two inches if you are topping up existing mulch. Keep it pulled back a few inches from trunks and stems: piled against bark it holds moisture where you least want it.
By the yard wherever the supplier allows it. Volume is what your project consumes; weight is what the truck carries, and the same yard weighs differently in July and in November. Where a yard only sells by weight, use the range above to convert and round up.