Mulch Calculator
Find out exactly how many cubic yards or bags of mulch you need for your landscaping project. Supports multiple areas.
How to Calculate Mulch for Your Yard
Figuring out how much mulch you need comes down to a simple formula: measure your area in square feet, pick your desired depth, and convert to cubic yards. Our calculator handles all the math, but here's how it works under the hood.
Cubic Yards = (Length × Width × Depth in inches) ÷ 324
The number 324 converts square feet × inches into cubic yards (since 1 yd³ = 27 ft³ = 46,656 in³).
Choosing the Right Depth
Most landscaping projects call for 2 to 4 inches of mulch. Use 2 inches for densely planted flower beds where you just need weed suppression. Go with 3 inches for most general purpose applications — it's the sweet spot between coverage and cost. Use 4 inches for pathways, play areas, or beds where you want maximum weed control. Avoid going deeper than 4 inches, as excessive mulch can trap moisture against plant stems and cause rot.
Mulch Coverage per Cubic Yard
| Depth | Coverage per yd³ | Bags per yd³ (2 cu ft) |
|---|---|---|
| 1 inch | 324 sq ft | 13.5 bags |
| 2 inches | 162 sq ft | 13.5 bags |
| 3 inches | 108 sq ft | 13.5 bags |
| 4 inches | 81 sq ft | 13.5 bags |
Bulk vs. Bagged Mulch
Buying in bulk is almost always cheaper for projects over 3 cubic yards. Bulk mulch runs $25–$60 per cubic yard depending on type, while bagged mulch from home improvement stores costs roughly $4–$7 per 2 cu ft bag — equivalent to $54–$95 per cubic yard. For small garden beds, bags are more convenient. For anything larger, bulk delivery saves significantly. Most landscape supply companies offer delivery for an additional $30–$75.
Frequently Asked Questions
Multiply your area's length × width (in feet) to get square footage, then multiply by desired depth (in inches), and divide by 324. For example, a 20×10 ft area at 3 inches deep needs: 200 × 3 ÷ 324 = 1.85 cubic yards. Round up to 2 cubic yards to account for settling and uneven terrain.
Most landscapers recommend 2–4 inches. Use 2 inches for flower beds with dense plantings, 3 inches for general landscaping (the most common choice), and 4 inches for tree rings, pathways, and areas where maximum weed suppression is needed. Never exceed 4 inches as it can suffocate plant roots and trap excess moisture.
One cubic yard equals 27 cubic feet. A standard 2 cu ft bag gives you about 13.5 bags per cubic yard. If using larger 3 cu ft bags, you'll need about 9 bags per cubic yard.
Dry mulch weighs approximately 400–800 lbs per cubic yard depending on type and moisture content. Hardwood mulch averages around 600 lbs/yd³, while lighter options like pine bark are closer to 400 lbs/yd³. Wet mulch can weigh up to 1,000 lbs per cubic yard — important to consider if picking up in a truck.
Late spring (after the soil has warmed) is ideal for most regions. This timing helps retain soil moisture through summer and suppresses weeds during peak growing season. A second application in late fall can protect plant roots over winter. Avoid mulching too early in spring before soil warms, as it can delay plant growth.