Bags vs. Bulk: How to Calculate Mulch and Soil for Garden Beds

Spring has arrived, and it's time to refresh the garden beds. But standing in the garden center staring at pallets of mulch bags can be overwhelming. How many bags do you actually need? Should you just order a dump truck full of bulk mulch instead?

Here is everything you need to know to calculate your landscaping materials.

The Math Behind Mulch

Landscaping materials are measured by volume. To find out how much you need, you have to calculate the cubic feet of your garden beds.

1. Measure the length and width of the garden bed in feet.
2. Determine how deep you want the mulch (usually 2 to 3 inches for weed suppression).
3. Convert the depth to feet (e.g., 3 inches = 0.25 feet).
4. Multiply Length × Width × Depth.

Example: A 20ft by 5ft bed needing 3 inches of mulch requires 25 cubic feet of mulch.

Bags vs. Cubic Yards

When you buy mulch, you have two options: buying bags from a home improvement store, or ordering bulk "cubic yards" from a local nursery.

• A standard bag of mulch is 2 cubic feet.
• A bulk cubic yard is 27 cubic feet (which is equal to 13.5 standard bags).

In our example above (25 cubic feet), you would need to buy 13 bags of mulch, or you could order 1 cubic yard of bulk mulch.

The Golden Rule of Cost

As a general rule, if your calculation requires more than 13 bags, it is usually cheaper and easier to order 1 cubic yard delivered in bulk. Bulk mulch is significantly cheaper per cubic foot than bagged mulch, though you do have to factor in the delivery fee.

Calculate It Instantly

Skip the complex volume math! Use our free Mulch & Soil Calculator. Just enter your bed's dimensions and your desired depth, and it will instantly tell you exactly how many bags or cubic yards you need to get the job done.