Mulch Calculator
Cubic yards
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Bags needed
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Add 10% extra for settling and waste.
Enter area and depth above
How Much Mulch Do You Need?
Mulch, gravel, and topsoil are all sold by the cubic yard for bulk delivery and in bags at garden centers. One cubic yard covers 108 square feet at 3 inches deep — a common rule of thumb. Knowing your square footage and desired depth is all you need to calculate how much to order.
Recommended Depths by Material
Bags vs. Bulk Delivery
Bagged mulch is convenient for small areas — one standard 2 cu ft bag covers about 8 sq ft at 3 inches deep. Bulk delivery is more economical for larger areas: one cubic yard (13.5 bags) typically costs $25–$50 delivered versus $5–$8 per bag at a garden center. The break-even point is usually around 10–15 bags.
Frequently Asked Questions
Should I put down landscape fabric first?
Landscape fabric under mulch helps suppress weeds but can impede water and air flow to roots and eventually degrades, becoming a nuisance. Many gardeners prefer thick mulch (3–4 inches) without fabric — it suppresses weeds effectively and breaks down to enrich the soil over time.
How often should I refresh mulch?
Organic mulches (wood chips, bark) break down over 1–2 years. Top up or replace when the layer compresses to less than 1–2 inches. Spring is the most common time to remulch — before summer heat and after the ground has warmed slightly.
How deep should mulch be?
For most organic mulches like wood chips and bark, 2–4 inches is the right depth. Less than 2 inches is too thin to suppress weeds effectively. More than 4 inches can prevent water from reaching roots and may cause fungal problems. Keep mulch 2–3 inches away from plant stems and tree trunks to prevent rot.
How many bags of mulch equal a cubic yard?
It depends on bag size. A standard 2 cubic foot bag means you need 13.5 bags to equal one cubic yard (since 1 cubic yard = 27 cubic feet). Larger 3 cubic foot bags require only 9 bags per yard. This calculator factors bag size in automatically so you can order the exact quantity you need.