#57 Gravel Calculator: How Many Tons of #57 Stone You Need
Figuring out how many tons of #57 gravel to order comes down to your area, your depth, and the density of the stone.
#57 Gravel Calculator (Tons & Cubic Yards)
Enter your area and depth to estimate #57 stone in cubic yards and tons, with a waste allowance.
Estimate only. #57 stone is open-graded and drains well; it does not compact into a hard surface on its own.
Here is how much ground one ton of #57 gravel covers at the depths people use most, based on a planning density of 1.4 tons per cubic yard.
| Spread depth | Area covered by 1 ton |
|---|---|
| 2 inches | about 116 sq ft |
| 3 inches | about 77 sq ft |
| 4 inches | about 58 sq ft |
| 6 inches | about 39 sq ft |
What #57 Gravel Actually Is
#57 is not a size in inches. It is a gradation number from the AASHTO M43 and ASTM D448 standards, which sort crushed stone by the sieve sizes it passes through rather than by a single diameter. A load labeled #57 is a clean, angular, open-graded blend that runs from roughly 3/8 inch up to 1 inch, with most pieces near 3/4 inch.
That open grading is the whole point. Because the pieces are uniform and there are no fines to pack the voids, #57 stone drains freely and stays loose instead of locking up tight. That makes it the default choice for driveways, drainage layers, French drains, pipe bedding, and a base under concrete or pavers.
Density Varies by Rock Type
The stone’s weight per cubic yard is what turns your volume into an order in tons, and it shifts with the parent rock:
- Crushed limestone: roughly 1.3 tons per cubic yard
- Washed gravel or a general planning figure: about 1.4 tons per cubic yard
- Granite: heavier, up to about 1.5 tons per cubic yard
Published specifications bear this out. A Louisiana DOT sheet for #57 limestone lists a dry-rodded unit weight of 92 pounds per cubic foot, which works out to roughly 1.24 tons per cubic yard, and a looser dry weight near 81 pounds per cubic foot. When you do not know the source rock, 1.4 tons per cubic yard is the safe middle for estimating.
How to Calculate #57 Gravel Tonnage
The math is four short steps:
- Area: length x width, in feet, to get square feet.
- Volume in cubic feet: area x (depth in inches / 12).
- Volume in cubic yards: cubic feet / 27.
- Tons: cubic yards x density (about 1.4 for #57).
As a worked example, a pad 10 ft wide by 40 ft long at a 4-inch depth is 400 sq ft. That is 400 x 0.333 = 133 cubic feet, or about 4.9 cubic yards. At 1.4 tons per cubic yard, you need roughly 6.9 tons of #57 stone before any allowance for waste.
How Deep to Spread #57 Gravel
Depth is where most orders go wrong, so match it to the job:
- Top-dressing an existing driveway: 2 to 3 inches.
- A full new gravel driveway: 4 to 6 inches total, usually over a coarser base layer such as #3 or #4 stone.
- French drains and trench backfill: fill the full trench depth around the pipe.
- Base under pavers, slabs, or sheds: about 4 inches, sometimes more on soft ground.
Spreading #57 too thin is the most common error. Under about 2 inches the clean stone scatters and shifts underfoot because there is nothing to bind it.
Why You Should Add a Waste Allowance
A tonnage calculation gives you the stone that fits the exact box you measured. Real ground is never that tidy. Uneven subgrade, spillage during spreading, and stone that works down into soft soil all eat into coverage, so order a little extra.
For #57 stone, add about 10 percent. Because it is open-graded, it does not compact down the way dense-graded material does, so you rarely need the 15 percent buffer that crusher run or screenings call for. On very soft or rutted ground, bump the extra toward 15 percent.
Common Mistakes When Ordering #57 Stone
- Buying by the bag for a big job. Bagged stone costs far more per ton than bulk. Past roughly a cubic yard, bulk delivery is almost always cheaper.
- Using the wrong density. Ordering granite tonnage for a limestone price, or the reverse, throws the total off by 10 to 15 percent.
- Forgetting it stays loose. #57 will not pack into a hard surface on its own. If you want a firm, bound driveway top, a dense-graded material belongs in the mix.
- Rounding depth down. Measuring 3 inches and ordering for 2 leaves you short by a third.
FAQ
How many tons of #57 gravel are in a cubic yard?
About 1.3 to 1.5 tons, depending on the rock. Limestone sits near 1.3, washed gravel near 1.4, and granite can reach 1.5.
How much area does 1 ton of #57 stone cover?
Roughly 58 sq ft at 4 inches deep, about 77 sq ft at 3 inches, and about 116 sq ft at 2 inches.
Does #57 gravel compact?
Not much. It is clean and open-graded, so it drains well and stays loose rather than locking into a hard surface. That is why it is favored for drainage but paired with a base layer for driveways.
What size is #57 stone?
Pieces run from about 3/8 inch to 1 inch, clustered around 3/4 inch. The “57” is a gradation code, not a measurement.
How much extra should I order?
Add about 10 percent for waste and settling on firm ground, and closer to 15 percent on soft or uneven subgrade.
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