Quick answer: At 3 inches deep, a 2 cu ft bag of mulch covers about 8 sq ft and one cubic yard covers about 108 sq ft. A 10 × 10 ft bed needs 25 cu ft, which is 13 bags or just under one cubic yard.
Mulch keeps moisture in the soil, suppresses weeds and makes beds look finished. Buying the right amount is simple once you know the area of your beds and how deep you want the mulch.
Step 1: Measure the Area
- Rectangular beds: length × width.
- Round beds and tree rings: 3.14 × radius × radius.
- Irregular beds: split them into rectangles and circles, then add the areas together.
Step 2: Choose the Depth
Most beds need 2–3 inches (5–7.5 cm) of mulch. Use up to 4 inches for stronger weed control in new beds, and 1–2 inches when topping up an existing layer.
Step 3: Calculate the Volume
Cubic feet = Area (sq ft) × Depth (in) ÷ 12
Cubic yards = Cubic feet ÷ 27
Bags = Cubic feet ÷ Bag size (cu ft)
Example: a tree ring 6 ft across has a radius of 3 ft, so its area is 3.14 × 3 × 3 = 28.3 sq ft. At 3 inches deep that is 7.1 cu ft, or 4 bags of 2 cu ft mulch.
Skip the math: enter your bed size and depth and get cubic yards, m³, litres and the number of bags. Open the free Mulch & Topsoil Calculator →
Mulch Coverage Chart
| Depth | One 2 cu ft bag covers | One cubic yard covers |
|---|---|---|
| 1 in | 24 sq ft | 324 sq ft |
| 2 in | 12 sq ft | 162 sq ft |
| 3 in | 8 sq ft | 108 sq ft |
| 4 in | 6 sq ft | 81 sq ft |
There are 13.5 bags of 2 cu ft in one cubic yard. In metric, a 50 litre bag covers about 0.67 m² at 7.5 cm deep, and 1 m³ (20 bags of 50 litres) covers about 13 m².
Bags or Bulk?
Bags are convenient for small areas and easy to carry. Once you need more than 2–3 cubic yards, bulk mulch delivered by a landscape supplier is usually much cheaper per yard. Bulk mulch can be messy, so have a tarp ready where the truck tips it.
Mulching Tips
- Weed and water the bed before spreading mulch.
- Keep mulch 2–3 inches away from tree trunks and plant stems to avoid rot.
- Avoid piling mulch into volcano shapes around trees.
- Top up once a year; organic mulch breaks down and feeds the soil.
- Using stone instead? Try our gravel calculator.
Frequently Asked Questions
How many bags of mulch are in a yard?
13.5 bags of 2 cu ft, 9 bags of 3 cu ft or 18 bags of 1.5 cu ft.
How much mulch do I need for 1,000 square feet?
At 3 inches deep, 1,000 sq ft needs 250 cubic feet, which is about 9.3 cubic yards or 125 bags of 2 cu ft.
How deep should mulch be?
2–3 inches for most beds. Thicker layers can stop water reaching the soil, and thinner layers let weeds through.
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Try the free Mulch & Topsoil Calculator or browse all home improvement calculators.