Gardening season is in full swing as evidenced by all the requests for soil and mulch we receive from our website. As part of these requests we get a common question: How much do I need? We thought it would be helpful to walk through a few real-world examples.

First, some background info on calculations and products.

• To know the root of calculations, there are 27 cubic feet in a cubic yard (3’ x 3’ x 3’), the common measurement for selling soil and mulch.
• To get a sense of volumes, a full-size pickup truck holds about 2 cubic yards. A volkswagon beetle is roughly the same volume as 15 cubic yards.

Next, let’s walk through a few real-world examples and calculate how much material is needed for a project.

NOTE: If you want to skip learning the math, then head straight over to our landscape calculator.

EXAMPLE #1: We need soil for two 8′ x 4′ x 18″ raised beds.

(~BD in Windsor Locks, CT)

Okay, BD. Let’s figure this out. So first let’s pretend these two raised beds are stretched end-to-end. They would measure 16’ long x 4’ wide and 18” tall. Now let’s go through the steps

• Convert all dimensions into feet (18” ÷ 12” = 1.5’)
• Multiply length x width x height (16’ x 4’ x 1.5’ = 96 cubic feet)
• Divide (96 ÷ 27 = 3.56 cubic yards)

Therefore, you’ll need about 3.5 cubic yards of garden blend for this project. We recommend rounding up to 4 cubic yards since you can almost always use more product top-dressing your lawn, the raised beds, or mixed into potting containers.

EXAMPLE #2: “How much mulch do I need to cover a 20’ x 30’ new garden with 3” of soil amendment?”

(~NM in Surrey, BC)

1. Convert all dimensions from inches into feet. (3” ÷ 12” = .25 feet)
2. Multiply the three dimensions together (length x width x height) to find the number of cubic feet needed. (20’ long x 30’ wide x 0.25’ high = 150 cubic feet)
3. Divide the cubic feet by the number of cubic feet in a cubic yard (27) to find the number of cubic yards (150 ÷ 27 = 5.56 cubic yards)

There you go, NM: You will need about 5-6 cubic yards for your project!

EXAMPLE #3: I’m covering my front- and back- landscape with 2” of mulch. The area is about 20’ x 10’. I want to know how much product I’ll need in bags since I don’t have a pickup truck or trailer, and I think it might be easier to pick up a bunch of product in my car and then carry them throughout the property instead of dealing with a wheelbarrow.

(~KH in Virginia)

Okay, KH. Here we go, with a modified step to convert to bags.

• Convert all dimensions into feet (2” ÷ 12” = 0.16’)
• Multiply length x width x height (20’ x 10’ x 0.16’ = 33 cubic feet)
• FOR CUBIC YARDS, we’d divide (33 ÷ 27 = 1.23 cubic yards). BUT INSTEAD we want to find out how many bags of mulch KH needs. So if she wants 1-cubic foot bags she’ll need to divide by 1 (33 ÷ 1 = 33 1-cubic foot bags). If she wants 2-cubic-foot bags she’ll need to divide by 2 (33 ÷ 2 = 17 2-cubic-foot bags).

Voila, our landscape calculator comes to the same conclusions (see screenshot).

Feeling inspired?

Hopefully this post helps you get a feel for dimensions and how much product you’ll need for your next landscaping project. We offer many quality soil and mulch products in bulk and bagged quantities. Or simply head on over to our contact page to request a quote. Happy landscaping!