How Do I Calculate How Much Rock I Need? Stone Coverage Formulas. 

Are you planning a project that involves landscaping rocks? Congratulations! You are making a rock-solid investment that will bring you enjoyment for many years. Let’s get the measuring tape and calculator out and help you figure out exactly how much cubic yards or tons you need to buy for your stone coverage requirements.

How Is Stone Coverage Calculated?

Stone is priced either by volume, which is calculated in cubic yards; or by weight, which is calculated in tons. We’re about to show you how to calculate what you need in either measurement unit.

Option 1: Cubic Yards

Step 1: Measure length and width in feet to calculate the area you need to be covered.

Whether you are covering a driveway, mulching a garden bed or creating a dry creek, the first thing you need to measure is the area to be covered. How long is it in feet? How wide is it in feet? Once you have those numbers, multiply them using the formula you learned in elementary school:

Length X Width = Area

Step 2: Measure how high you'd like the rock in inches (depth).

You may need some advice to determine how deep your stone coverage should be. For example, if you are using stone for mulching, 1 ½ or 2 inches are plenty. If you’re covering a driveway, the recommendation is at least 4 inches.

If you’re not sure which depth is appropriate, reach out to us, and we’ll be happy to advise you.

Once you know the depth of decorative stone you want, in inches, use this other formula:  

Area X Depth = ??

Step 3: Divide this by 324.

Once you have multiplied all three numbers, all you have to do is divide your result by 324 to get the number of cubic yards of decorative stone you need for your project. 

??? / 324 = cubic yard

Option 2: Tons

Step 1: Measure length and width in feet to calculate the area you need to be covered.

Take out your tape measure, and get the length and width of the fire pit, path or focal point you want to fill with decorative stone. Make sure your measurements are in feet, and then multiply them to get the area.

Length X Width = Area

Step 2: Measure how high you'd like the rock in feet (depth).

The depth of rock will depend on the type of project - if you’re using stone as a groundcover and you want to prevent weeds from sprouting, use at least 3 inches. Remember there are 12 inches in one foot.

Multiply the previous result by the depth in inches you want to reach.

Area X Depth = ??

Step 3: Divide this by 21.6 (the number of cubic feet in a ton).

What you have right now is the volume of rock you need, which we converted to cubic yards with the previous formula. Since what you want now is the weight, divide your result by 21.6, and this will give you the number of tons required for your project.

??? / 21.6 = tons

How Many Square Feet Does a Ton of Rock Cover?

Decorative stone can cover more or less area depending on its size, shape and other characteristics. Fortunately, there are tables you can use as a reference if you want to validate your results from the previous formulas.

use info from tables here:

Decorative Stone Solutions Available Nationwide

Remember, we are always happy to answer your decorative stone questions! We have colors and sizes you will not find in other places, and we ship them nationwide! Give us a call anytime you want to talk about landscaping rocks.