When you’re planning a project involving landscaping rock, a key question is how much material you will need.
Calculating accurately can save you money and headaches. You don’t want to order too little rock and not have enough to adequately cover your landscape. But if you order too much, you’ve wasted money—and wasted labor spreading it around.
There are two factors to consider when calculating the amount of landscape rock to order for your project:
- The size of the space you’re covering
- How deep you want the coverage
To calculate the size, measure the length and the width of your project area. Multiply those two numbers to come up with the square footage of your coverage area. So if your project is 18 feet long by 20 feet wide, your coverage area is 360 square feet.
Next decide how deep you want your coverage. For most purposes, about 2 inches of material will be adequate. If you’re using materials that are themselves larger than 2 inches, then the depth will probably be the size of the rocks, that is, you’ll just want one layer of 3-8 inch rocks.
The amount of landscaping rock you’ll need depends partly on what size of rock or gravel you want to use. This chart gives you some general estimates of how large an area 1 ton of several different types of material will cover.
Calculating Rock Needs
Material | Suggested Depth | Coverage Area per 1 ton |
3”-8” rock | 3”-8” | 60 square feet |
1”-3” rock | 1”-3” | 80 square feet |
3/4”-1” screened gravel | 2” | 100 square feet |
5/8”-1/2” screened gravel | 2” | 120 square feet |
1/4-3/8” screened gravel | 2” | 140 square feet |
Use this chart to come up with the amount of material you’ll need. You’ll take the square footage you came up with earlier when you measured your project area, then divide it by the coverage area number in the table above for the material you’re using.
So if you’re using recommended depth in the chart above, the basic formula you need is this:
L × W = Square footage of coverage area.
Square feet of coverage area ÷ coverage area per 1 ton = tons of rock needed.
Using this formula, you can see that if you’re looking to cover 360 square feet with 1”-3” size rocks, you’re probably going to need 4.5 tons. If you’re using smaller materials, say 3/4”-1”, you may need only 3.6 tons.
The team at MDI Rock is happy to help you figure out the depth of coverage you need for your project and help you calculate how much material you need. With more than 50 different kinds of decorative groundcover, we can also work with you to choose the right kind of material for your project.
We’re happy to work with all types of clients—professional landscapers or do-it-yourselfers—on their landscaping projects. No project is too big or too small.
We also deliver. MDI maintains a fleet of dump trucks and can deliver anywhere from across the street to across the country.
