Quantity calculator

Rock Calculator for One Bed

Estimate one rectangle, full circle or known area in cubic yards, estimated US short tons and half-cubic-foot bags. Use the main calculator for rings, triangles, trapezoids and L-shaped areas.

Measure:Rectangle, full circle or known area
Enter:Finished depth and extra material
Estimate:Cubic yards, short tons and 0.5 cu ft bags

Example: A 12 × 10 ft bed at a finished depth of 3 in needs 1.11 yd³ of rock. With the tool's default 10% extra, order volume becomes 1.22 yd³ — about 1.62 short tons using its 1–3 in river-rock preset, or 66 bags if each bag holds 0.5 cu ft.

Estimate Rock for Your Measured Area

Choose a rectangular bed, a full circle, or known square footage. Enter finished rock depth and extra material to see the volume to order.

Bed Geometry Shape

feet
feet
inches
% extra

Rock Density Preset

These are planning weight factors, not measured weights for a particular delivery. For a supplier-provided density, use the full rock coverage calculator.

Estimated Order Quantities
River rock (1–3 in) (1.325 US tons/yd³)
0.00
Volume to Order (Cubic Yards)
0 cu ft including extra
0.00
Estimated Weight (Short Tons)
0 lbs including extra
0
0.5 Cu Ft Bags (Whole)
0 pallet equivalents at 60 bags each
0
Wheelbarrow Loads
At 6 cu ft per full load
Project Surface Area420 sq ft
Fabric Estimate (10% Overlap)462 sq ft (2 rolls)
Coverage per Cubic Yard at This Depth108 sq ft per cubic yard

The estimate, unpacked

From bed measurements to an order quantity

The tool starts with the space the rock will occupy. It then adds your extra-material percentage before converting the result to weight, bags and wheelbarrow loads. A cubic yard contains 27 cubic feet; a US short ton contains 2,000 pounds.

Sample field takeoff12 ft × 10 ft × 3 in
  1. Bed area12 × 10 = 120 sq ft
  2. Rock volume before extra120 × 3 ÷ 324 = 1.11 yd³
  3. Order volume with 10% extra1.11 × 1.10 = 1.22 yd³
  4. Estimated weight at 1.325 tons/yd³1.22 × 1.325 ≈ 1.62 short tons
  5. 0.5 cu ft bags33 cu ft ÷ 0.5 = 66 bags

Displayed figures are rounded. The calculator uses unrounded values for each conversion and rounds the bag count up to a whole bag.

Measure once, enter the right shape

Use the area that will actually receive rock

Measure to the inside of your edging and subtract large footprints that will stay uncovered. Enter the finished layer depth, not the depth of an excavation below a separate base course.

Rectangle bed area and rock layer depthTop view of a 12-foot by 10-foot rectangle beside a cross-section of a 3-inch rock layer.12 ft length10 ft width120 sq ftrock layer3 in deep
Area × installed depth gives volume. The drawing is a measurement guide, not a rock-size specification.

Rectangle or strip

Enter length and average width in feet. Break an L-shaped bed into rectangles, add their areas, then use Known Area.

Full circle

Enter the diameter across the entire circle. This mode includes the center of the circle.

Tree or fire-pit ring

Subtract the center opening first: 0.7854 × (outer diameter² − inner diameter²). Enter the remaining square feet under Known Area.

Before calling the supplier

Match the estimate to the material you will buy

Volume is controlled by the footprint and depth. Weight depends on the loose bulk density of the particular rock; changing the material preset changes tons, not cubic yards.

01

Set a realistic layer depth

For decorative inorganic mulch around plantings, 2–3 inches is a useful starting range. Larger stone or exposed fabric may call for a deeper layer. A driveway base has different compaction requirements; plan it as a separate layer.

Use the depth guide →
02

Confirm the weight conversion

This tool starts at 1.325 US tons/yd³ for 1–3 in river rock, 1.4 for 3/4 in crushed granite, 1.25 for 1/4 in minus decomposed granite, and 0.75 for 3/4–2 in lava rock. Ask your supplier for its product's conversion; a scale ticket records the actual delivered weight.

Understand bulk density →
03

Check the sales unit

The bag result assumes each bag contains 0.5 cu ft. A bag sold by pounds can contain a different volume. The 10% default extra covers small low spots and handling; change it if you have a measured need or unusually even ground.

Compare bulk and bags →

Tool scope: The volume, weight, bag and wheelbarrow results include the selected extra-material allowance. The fabric line estimates 10% overlap separately and assumes 3 × 100 ft rolls; check your actual roll size. Wheelbarrow trips assume a full 6 cu ft load. These are planning quantities, not a certified scale weight or a vehicle payload recommendation.

Rock calculator questions

How do I calculate cubic yards of rock?

Multiply the area in square feet by the finished rock depth in inches, then divide by 324. A 120-square-foot bed at 3 inches needs 1.11 cubic yards before any extra material. The calculator adds your selected allowance to its displayed order volume.

Does one cubic yard of rock always weigh the same?

No. Rock type, grading, void space and moisture change the delivered weight. The calculator uses its selected material preset as a planning estimate. Ask the supplier for the loose bulk density or a product-specific tons-per-yard conversion before placing a weight-based order.

Can the circle input calculate a rock ring around a tree or fire pit?

The circle input calculates the whole circle. For a ring, subtract the inner circle from the outer one: ring area in square feet = 0.7854 × (outer diameter² − inner diameter²), with both diameters in feet. Enter that result under Known Area.

Are the bag results based on 50-pound bags?

No. The bag count divides the allowance-inclusive volume by 0.5 cubic foot and rounds up to a whole bag. Bag weight varies by material; check the package volume on the product you plan to buy.