Stone and landscape rock calculator

A 10 × 10 ft bed at 3 inches is 0.93 cubic yards of river rock, or 50 bags of 0.5 cubic feet (about 1.16 tons at 1.25 tons per cubic yard).

You need 0.93 cubic yards (25.00 cubic feet, about 1.16 tons at 1.25 tons per cubic yard).

At 3 inches, one ton covers about 86.4 square feet.

Order about 0.93 cubic yards (1.16 tons at 1.25 tons per cubic yard), or 50 bags (0.5 cu ft).

Report a problem with this result

How we calculated this

10 ft × 10 ft × 3 in (0.250 ft) = 25.00 cubic feet. Divided by 27, that is 0.93 cubic yards.

Typical dry river rock is about 1.2 to 1.35 tons per cubic yard (EPA pebble range); we use 1.25.

We used river rock at 1.25 tons per cubic yard, which gives 1.16 tons.

No extra was added for waste. You can add some under More options if your ground is uneven.

Typical dry river rock is about 1.2 to 1.35 tons per cubic yard from the EPA conversion table (FEECO: pebbles 90–100 lb per cubic foot). We use 1.25, the same planning figure as pea gravel.

At 3 inches, one ton covers about 86.4 square feet.

Small rock is often about 2 inches (University of Nevada Extension: a two inch layer of rock over fabric). 1 to 3 inch river rock is 2 to 3 inches (Utah State Extension inorganic mulch). Larger rock is 3 to 4 inches (Colorado State Extension, most mulches including pea gravel). This page notes depths under 2 inches or over 4.

Decorative beds, paths, and borders belong here. Driveways and compacted bases belong on the gravel calculator.

Estimate cost (optional)

Your price per ton$

Sources

River rock defaults to 1.25 tons per cubic yard from the U.S. Environmental Protection Agency (federal agency, 2016) (opens in a new tab) conversion table: “Pebbles” 90–100 lb per cubic foot, or about 1.2 to 1.35 tons per cubic yard. We use 1.25, the same planning figure as pea gravel. Crushed stone on this page is the same EPA row already cited: “Stone, crushed” 100 lb per cubic foot and “Stone, crushed, size reduced” 2,700 lb per cubic yard, both 1.35 tons per cubic yard.

Lava rock is scoria, not pumice. New Mexico Bureau of Mines Bulletin 24 (state geological survey, Clippinger, 1946) (opens in a new tab) lists crushed scoria at 1,000–1,500 lb per cubic yard (0.50–0.75 tons). We use the low end, 0.50. Decomposed granite uses 1.50 tons per cubic yard from the GraniteCrete math sheet (manufacturer, revised July 29, 2024) (opens in a new tab): one cubic yard of decomposed granite equals 1.5 tons. Marble chips are omitted: QUIKRETE sells them in 0.5 cubic foot bags but publishes no bulk density.

Bags default to 0.5 cubic feet from the QUIKRETE 2015 Product Guide (manufacturer) (opens in a new tab): River Pebbles, Red Lava Rock, All-Purpose Stone, and Marble Chips are each 0.5 cubic feet (63 per pallet).

HomeGuide, Landscaping River Rock Prices (cost guide, Sarah Noel, December 19, 2025) lists river rock at about $50 to $160 per cubic yard and $45 to $130 per ton, and a coverage band of about 55 to 135 square feet per ton at 2 to 4 inches: HomeGuide, Landscaping River Rock Prices (cost guide, December 19, 2025) (opens in a new tab). This page’s coverage table uses the cited 1.25 tons per cubic yard (129.6, 86.4, and 64.8 square feet per ton at 2, 3, and 4 inches).

Depth: small rock about 2 inches from University of Nevada, Reno Extension, Mulches for Nevada Landscapes (university) (opens in a new tab), landscape fabric under a two inch layer of rock; 1 to 3 inch river rock 2 to 3 inches from Utah State University Extension, Water-Wise Landscaping: Mulch (university, March 2007) (opens in a new tab), inorganic mulch; larger rock 3 to 4 inches from Colorado State University Extension 7.214, Mulches for Home Grounds (university) (opens in a new tab), most mulches including pea gravel. A note appears under 2 inches or over 4.

A 10 × 10 ft bed at 3 inches needs 0.93 cubic yards of river rock, or 50 bags of 0.5 cubic feet (about 1.16 tons at 1.25 tons per cubic yard). Volume does not change with the rock type. Tons do, because lava rock is much lighter than river rock or crushed stone.

This page is for decorative landscape rock in beds, paths, and borders. For driveways and compacted bases, use the gravel calculator.

Enter length and width in feet. Add another area for a second bed. For a round bed, open More options, choose Circle, and enter the diameter.
Set depth in inches. Three inches is a common 1 to 3 inch river-rock bed. A note appears if you go under 2 inches or over 4.
Choose river rock, crushed stone, lava rock, or decomposed granite.
Leave bags on 0.5 cubic feet unless the sack is larger. The count rounds up.
Order 0.93 cubic yards, or 50 bags of 0.5 cubic feet, for the default 10 × 10 ft bed at 3 inches.

Length × width × (inches ÷ 12) gives cubic feet. Divide by 27 for cubic yards. Bags = cubic feet ÷ 0.5, rounded up. Tons = cubic yards × the cited density for that material. Square feet per ton = 27 ÷ (tons per cubic yard × depth in feet).

How much landscape rock do I need?

Multiply length by width by depth in feet, then divide by 27. A 10 × 10 ft bed at 3 inches is 100 × 0.25 ÷ 27 = 0.93 cubic yards, which is 25 cubic feet, or 50 bags of 0.5 cubic feet. At 1.25 tons per cubic yard of river rock that is about 1.16 tons. Cubic yards = L × W × depth in ft ÷ 27. The rock type does not change the yards; it only changes tons.

Worked example: 10 × 10 ft bed at 3 inches

Worked example

A 10 by 10 ft bed, 3 inches of river rock, no extra for waste, 0.5 cubic foot bags.

10 × 10 = 100 square feet. Three inches is 0.25 feet. 100 × 0.25 = 25 cubic feet. 25 ÷ 27 = 0.93 cubic yards. 25 ÷ 0.5 = 50 bags. At 1.25 tons per cubic yard, 0.93 × 1.25 = 1.16 tons.

Those are the default numbers on this calculator. Lava rock at 0.50 tons per cubic yard would be about 0.46 tons for the same yards.

River rock coverage per ton

Depth	Square feet covered by 1 ton of river rock
2 in	129.6 sq ft
3 in	86.4 sq ft
4 in	64.8 sq ft

Coverage is 27 ÷ (1.25 × depth in feet) at the cited river-rock density. The 10 × 10 ft default at 3 inches is 100 square feet, a little over a ton, or 50 bags of 0.5 cubic feet. Lava rock covers more area per ton because it is lighter.

Questions

How deep should landscape rock be?

Small rock is often about 2 inches (University of Nevada Extension over fabric). 1 to 3 inch river rock is 2 to 3 inches (Utah State Extension inorganic mulch). Larger rock is 3 to 4 inches (Colorado State Extension, most mulches including pea gravel). This calculator flags depths under 2 inches or over 4.

How much does a ton of river rock cover?

At 1.25 tons per cubic yard, one ton covers about 129.6 square feet at 2 inches, 86.4 square feet at 3 inches, and 64.8 square feet at 4 inches. HomeGuide (December 19, 2025) puts one ton at about 55 to 135 square feet at 2 to 4 inches, a wider band that includes heavier stone.

How much is a yard of river rock?

HomeGuide (cost guide, Sarah Noel, December 19, 2025) lists landscaping river rock at about $50 to $160 per cubic yard. Delivery is extra. Type your quote under Estimate cost.

How much is a ton of river rock?

The same HomeGuide page (December 19, 2025) lists river rock at about $45 to $130 per ton. Color, size, and haul distance move the ticket. Type your quote under Estimate cost.

Is mulch or rock better for landscaping?

Rock lasts longer and does not blow away; it does not feed the soil as it sits. Mulch cools soil, adds organic matter as it breaks down, and needs topping up. Utah State Extension treats both as mulch: organic at 3 to 4 inches, inorganic rock at 2 to 3. Pick rock for paths and low-water beds, mulch where you want soil life. Use the mulch calculator for bags and yards of wood mulch.

How many bags of rock are in a yard?

A cubic yard is 27 cubic feet, so 54 bags of 0.5 cubic feet. This page rounds the job up, so the default 25 cubic feet is 50 bags. QUIKRETE’s 2015 product guide packs River Pebbles, Red Lava Rock, and All-Purpose Stone in 0.5 cubic foot bags (63 per pallet).

Written by The BuildMath team. Formulas tested against worked examples. Updated October 24, 2026.

Stone and landscape rock calculator

Sources