Cubic yards and the exact bag count for any bed shape and depth. Also handles topsoil, compost, gravel, and paver sand.
3" is standard for mulch. 6" for new raised beds. Paver sand: 1".
Bulk delivery saves money above ~3 cubic yards
Based on the dimensions on the left — edit them to match your project and this updates as you type.
10 bags — bulk delivery is cheaper over 3 yards but bags work for smaller areas
Tip: Bags are the right call for your area size.
1 rolls — blocks weeds under mulch or gravel
Tip: Use staples every 12" to hold fabric flat before adding mulch.
Pins fabric to ground so it doesn't shift
Keeps mulch contained and beds looking clean
Tip: Black aluminum edging is more durable than plastic and installs without stakes.
Mulch and topsoil bags shred bare hands
Spread and level mulch evenly — you'll use it constantly
Multiply the bed's square footage by the depth in feet to get cubic feet, then divide by 27 for cubic yards or by the bag size for a bag count. At the standard 3-inch depth, depth in feet is 0.25 — so a 100 sq ft bed needs 25 cubic feet, which is about 0.9 cubic yards or 13 bags of the common 2-cubic-foot size.
A cubic yard is 27 cubic feet, so it takes 13.5 bags of the standard 2-cubic-foot size — round up to 14 to actually fill a yard. If you are buying 3-cubic-foot bags it takes 9. That ratio is why bulk delivery starts winning on price once a job runs past a few yards: 3 cubic yards is roughly 41 two-cubic-foot bags to load, haul, and open by hand.
A 2-cubic-foot bag covers about 12 square feet at a 2-inch depth, 8 square feet at 3 inches, and 6 square feet at 4 inches. A 3-cubic-foot bag covers about 18, 12, and 9 square feet at those same depths. Coverage is just bag volume divided by depth in feet, so doubling the depth halves the area a bag covers.
Three inches is the standard for a new bed — deep enough to block light from weed seeds and slow moisture loss, shallow enough that water and air still reach the roots. Use 2 inches when you are topping up over mulch that is still in decent shape, and up to 4 inches on bare soil where weed pressure is heavy. Going past 4 inches works against you: it can keep water from reaching the root zone, hold damp against stems, and encourage fungal growth. Around a tree, keep mulch pulled back from the trunk flare rather than piled against it.
Bulk is sold by the cubic yard and adds a flat delivery fee, so it only wins once the volume is large enough to absorb that fee — commonly somewhere around 3 cubic yards, about 41 two-cubic-foot bags. Below that, bags usually come out ahead and are far easier to handle. Bulk also needs a spot for the pile to be dumped and a wheelbarrow to move it, which is worth factoring in before you order.
Usually not. Mulch breaks down into the soil, which is part of what it is there for, so most beds just need a top-up rather than a strip-out. Rake the existing layer to break up any crust and check the total depth first — if the bed is already sitting at 3 inches, adding another 3 puts you well past the point where mulch starts holding damp against stems. Remove the old layer only if it has matted into a water-shedding crust or is showing persistent fungal growth.