Mulch Coverage Cheat Sheet: Bags, Yards, and Depth

Start with square footage

Measure each bed's length and width in feet and multiply them. Add the beds together for a total area. A typical front-of-house bed might be 30 ft × 4 ft, or 120 sq ft.

Multiply by depth

Multiply the area by the depth in inches and divide by 12 to get cubic feet. For 120 sq ft at 3 inches: 120 × 3 ÷ 12 = 30 cu ft. Divide by 27 for cubic yards — about 1.1 cu yd. In 2 cu ft bags, that's 15 bags.

Coverage numbers worth remembering

• One 2 cu ft bag covers about 12 sq ft at 2 inches, or 8 sq ft at 3 inches
• One cubic yard covers about 162 sq ft at 2 inches, or 108 sq ft at 3 inches
• One cubic yard equals 27 cu ft, or 13.5 bags of 2 cu ft

Refreshing vs. starting fresh

If you already have mulch that's breaking down, you rarely need a full new layer. Check the existing depth with a trowel. If there are still 1–2 inches, topping up with an inch of fresh mulch is often enough and roughly halves the amount you buy.

Bags or bulk

Bagged mulch is easy to transport and store. Bulk mulch is usually cheaper per yard once you need more than a couple of yards, but it arrives as one pile, so plan where it'll be dumped and how you'll move it. Use the CalcAndPlan Mulch Calculator to get both the bag count and the yardage for a side-by-side comparison.