Mulch & Soil Calculator

Bulk landscape suppliers sell by the cubic yard; garden centres usually sell 2 cu ft or 1.5 cu ft bags.

One cubic yard spread 3 in deep covers about 108 sq ft.

Spreading material over a bed creates a thin slab, so the amount needed is a volume: area multiplied by depth. Area is entered in square feet, but depth is easier to picture in inches, so the tool divides the depth by 12 to convert it to feet before multiplying. The result is the volume in cubic feet.

Bulk landscape yards sell loose material by the cubic yard, which is a cube three feet on each side. One cubic yard holds 27 cubic feet, so dividing the cubic-foot figure by 27 gives the order quantity for a delivery or a trailer load.

Garden centres sell bagged material, most often in 2 cubic foot bags, although 1.5 and 3 cubic foot bags are also common. Dividing the cubic feet by the bag size and rounding up gives the number of bags. The tool also shows how far one cubic yard stretches at your chosen depth, which helps when comparing bulk prices with bagged prices. Fresh mulch and loose soil settle after watering, so it is wise to add a little extra.

Imagine a front flower bed of 200 square feet that you want to top with 3 inches of shredded bark mulch sold in 2 cubic foot bags.

Three inches is 0.25 feet, so the volume is 200 × 0.25, which equals 50 cubic feet. Dividing by 27 gives about 1.85 cubic yards, the amount you would order from a bulk supplier.

For bagged mulch, 50 cubic feet divided by 2 cubic feet per bag gives exactly 25 bags. If bags cost $4 each, that comes to $100, so a bulk delivery of two cubic yards could be worth comparing once the delivery fee is included.