How Much Crushed Stone Do I Need?

Calculate What's Needed for Your Patio, Driveway, or Yard This Formula

closeup of crushed stone

The Spruce / K. Dave

So you are planning this great DIY project that will spruce up your yard considerably. You are quite excited, but there is just one problem: It requires crushed stone,

For your project, the amount of crushed stone needed is not clarified. It's difficult to calculate and guessing is rarely a good solution to such dilemmas when undertaking a home improvement. We provide a (relatively) simple way to figure out the correct amount.

The word, "relatively" is used because a formula is involved. And for many of us, as soon as we hear the word, "formula," we feel uneasy as the anticipation of a DIY project then becomes a more technical operation. When the formula is actually provided for you, it is pretty easy to use. All you have to do is plug in some numbers.

Crushed Stone Project Formula

Formula for Needed Crushed Stone

Use this formula to determine how much crushed stone you will need for your project:

(L'xW'xH') / 27 = cubic yards of crushed stone needed

In the construction world, most materials are measured in cubic yards. Multiply the length (L), in feet, by the width (W), in feet, by the height (H), in feet, and divide by 27. This will tell you how many cubic yards of crushed stone you need.

As an example, let's say your DIY project is a patio, and it calls for the use of crushed stone as a base. If your patio is 20 feet long and 10 feet wide, and you need 6 inches of crushed stone for the base, you would plug those numbers into formula, as follows:

(20'x10'x0.5') / 27 = 3.7 cubic yards

When using this equation, make sure all of your measurements are in feet. Since we needed 6 inches of crushed stone, we used 0.5 feet for the height (that is, we converted inches into feet).

If your number comes out as a fraction (and it probably will), round up. In the example above, you would round the 3.7 cubic yards of crushed stone to 4 cubic yards of crushed stone. It is better to have a little extra than to run short.

  • Argillite: A construction aggregate with fire-resistant properties.
  • Basalt: Commonly used as the base for concrete mixtures. It's darker color provides a great design option, as it can be thinly cut to use as tile.
  • Gabbro: Referred to as "black granite," gabbro is a good choice for any projects that need to withstand impact such as pavers and ashlars.
  • Granite: A household favorite, chosen for its color and durability.
  • Grit: Finer stone used as a construction aggregate.
  • Limestone: The most popular crushed stone option, limestone is easily crushed and used in ready mix concrete, railroad ballast, and drain fields.
  • Quartzite: Used for road construction, rubble, and in between railroad tracks due to its durability.
  • Rip rap: Larger stone used for erosion control.
  • Sandstone: Used in concrete and masonry but sandstone is not ideal due to its challenging sediment nature.
  • Slate: A fine, clay material that's commonly used for sidewalk slabs, roofs, flooring, countertops and chalkboards.
  • Volcanic scoria: Lightweight and good for movable DIY concrete planters.
  • Washed gravel: Cleaned of all dirt and dust, which makes it a popular interior design choice.

What Is Crushed Stone

Crushed Stone is a man-made construction aggregate typically produced in a quarry by passing stones through a crushing machine. (Gravel, in contrast, is produced naturally). The crushed stone is typically used as a base or underlayment, for example, where the concrete of a patio will rest. It's also used for drainage and landscaping. It is offered in a variety of sizes and stones. Crushed stone can be purchased at home improvement stores, garden centers, or directly from a quarry.

Categories of Crushed Stone

Clean Stone

Clean crushed stone has been cleaned so there are limited traces of stone dust. It's commonly used for the top layer of a stone driveway or areas that can handle lighter impact.

Crushed Stone

Crushed stone typically has a residue of stone dust and is commonly used as a base to absorb heavy impact, notably on concrete and paving projects, foundations, and driveways.

Stone Dust

Stone dust has the fine consistency of sand that is created in the crushing process. It's used used when packing stone but can become problematic when water needs to drain.

Washed Clean Stone

Washed clean stone has been screened like clean stone, but then washed to remove all traces of stone dust. It's a common choice for drainage purposes, ready mix concrete, and design projects.

Crushed Stone Size

Crushed stone is often categorized by its size or grade, which is helpful to know when purchasing. Sizes range from #1, which is the largest available type at 2 to 4 inches, to a 3/4 inch variety used in asphalt mixes and driveways.

Did You Know?

In 2020, the Unites States produced 1.46 billion tons of crushed stone. That's an average of about four tons of crushed stone per American.

Crushed Stone vs. Gravel

The angular surface, roughness, and larger size of crushed stone make it a popular choice for gardens and pathways. It provides solid traction, doesn't easily sink into the ground, and resists weed growth. By comparison, granite has a rounder, more natural appearance that's a cost-effective option commonly used on driveways. For your next project, it really comes down to a matter of preference and use.

What Other Uses Are There for Crushed Stone?

Earlier mention was made of using crushed stone as a base for various DIY projects, such as those that would involve pouring a concrete slab. But this material has a wide range of applications in the landscape. While it often serves as a base for something else (in which cases no one actually sees it once the project is complete), this is not always the case. 

Crushed stone brings in a beautiful design element to a variety of spaces. It's functional by delineating areas, offers safe traction, and has a tranquil stylistic quality.

Limestone as an Acid Neutralizer in the Garden

Limestone is an alkaline agent with the ability to keep the soil pH higher. After it rains, the lime runs into the dirt and will help nourish your plants, prevent harmful lawn toxins from building up, and can improve the calcium levels in the soil. It also mixes well with fertilizer.

Crushed Stone Ideas