Mulch Calculator - Estimate Bags & Cubic Yards

How to Calculate Mulch

Mulch is sold by volume, typically in bags (cubic feet) or bulk (cubic yards). To find out how much you need, you calculate the volume of your garden bed.

Step 1: Calculate Area

Measure the length and width of your flower bed.
Area = Length × Width

Step 2: Determine Volume

Multiply the area by your desired depth (usually 3 inches). Ensure units match (convert depth to feet).
Volume (ft³) = Area (ft²) × (Depth (in) / 12)

Step 3: Convert to Yards or Bags

Cubic Yards: Divide Cubic Feet by 27. (1 yd³ = 27 ft³).
Bags: Divide Cubic Feet by the bag size (usually 2).

Example

A 10ft x 10ft garden bed needs 3 inches of mulch.
Area = 100 sq ft.
Volume = 100 × (3/12) = 25 cubic feet.
Cubic Yards: 25 / 27 ≈ 0.93 yards.
Bags (2 cu ft): 25 / 2 = 12.5 (Buy 13 bags).

? Frequently Asked Questions

One cubic yard is equal to 27 cubic feet. A standard bag is 2 cubic feet. Therefore, there are 13.5 bags in a cubic yard.

A depth of 2 to 3 inches is ideal. Less than 2 inches may not stop weeds, while more than 4 inches can suffocate plant roots and prevent water from reaching the soil.

Generally, yes. Bulk mulch sold by the cubic yard is often 30-50% cheaper than buying the equivalent volume in bags, but you usually have to pay a delivery fee.