Mulch Calculator
Calculate cubic yards and number of bags of mulch or soil needed for any garden bed.
How to Calculate Mulch Volume
The formula is: Volume (cu ft) = Length (ft) × Width (ft) × Depth (ft). Convert depth from inches to feet by dividing by 12. Then divide by 27 to get cubic yards.
Example: A 10 ft × 8 ft bed at 3-inch depth = 10 × 8 × (3/12) = 20 cu ft = 0.74 cu yd ≈ 10 bags of 2 cu ft.
Coverage at Common Depths
| Depth | Sq Ft / Cu Yd | Bags (2 cu ft) / Cu Yd |
|---|---|---|
| 1 inch | 324 | 13.5 |
| 2 inches | 162 | 13.5 |
| 3 inches | 108 | 13.5 |
| 4 inches | 81 | 13.5 |
1 cubic yard = 27 cubic feet = 13.5 bags of 2 cu ft each.
Frequently Asked Questions
How deep should mulch be applied?
The recommended mulch depth is 2–4 inches. Two inches is the minimum for effective weed suppression and moisture retention. Three inches is ideal for most applications. Avoid applying more than 4 inches, as very thick mulch can compact, repel water, and create habitat for pests and rodents.
How many cubic yards are in a bag of mulch?
A standard 2 cubic foot bag of mulch equals about 0.074 cubic yards. A 3 cubic foot bag equals about 0.111 cubic yards. Bulk mulch is sold by the cubic yard — 1 cubic yard equals 27 cubic feet and covers about 100 square feet at 3 inches deep.
What is the difference between mulch and topsoil?
Mulch is a surface covering (wood chips, bark, straw, etc.) applied to reduce weeds and retain moisture — it sits on top of the soil. Topsoil is actual soil that improves the growing medium. Use topsoil when establishing new beds; use mulch as an annual maintenance top-dressing.
When is the best time to apply mulch?
Spring (after the ground thaws) and fall are the best times to mulch. Spring mulching retains moisture during dry summer months. Fall mulching insulates plant roots against freeze/thaw cycles. Avoid mulching too close to plant stems to prevent rot — keep a 2–3 inch gap around trunks and stems.
How much does a cubic yard of mulch weigh?
A cubic yard of wood mulch weighs approximately 400–800 lbs depending on moisture content and wood type. Wet mulch can weigh significantly more. For delivery, a standard pickup truck can carry about 2 cubic yards of dry mulch. Check with your supplier for specific weight guidance.