Mulch Calculator
Enter your bed dimensions and desired depth to get the mulch you need in cubic yards, cubic feet, and standard bag counts.
Tip: for irregular beds, break them into rectangles and add the areas together.
How the math works
cubic yards = cubic feet ÷ 27
2 cu ft bags = cubic feet ÷ 2 (round up)
Mulch is sold by volume, and depth is the variable people get wrong. Because depth is entered in inches, we convert it to feet by dividing by 12 before multiplying by the bed area. One cubic yard equals 27 cubic feet — that's 13.5 bags of the common 2-cubic-foot size, which is why bulk delivery usually wins for anything over about 3 yards.
How deep should mulch be?
Use 2–3 inches to top up existing beds and 3–4 inches for new beds to block weeds. Going deeper than 4 inches suffocates shallow roots, keeps moisture against the bark, and can rot crowns of perennials. Always pull mulch a few inches back from tree trunks and stems.
FAQ
- How much area does one bag cover?
- A 2 cu ft bag covers about 8 sq ft at 3 inches deep, or 12 sq ft at 2 inches deep.
- Does mulch settle?
- Yes — wood mulch settles 10–20% in the first month, so err slightly high on fresh, fluffy product.
- Bags or bulk delivery?
- Under roughly 13 bags (half a yard), bags are easier. Beyond that, bulk mulch is usually 30–50% cheaper per yard.