How this instrument works
Crushed stone and gravel are sold by weight (tons), so estimating a project means converting the area you want to cover into a volume using the planned depth, then converting that volume into weight using the material's density — the same basic approach used for asphalt and other bulk aggregate materials.
Crushed stone under 2 inches typically weighs around 1.4 tons per cubic yard as a commonly cited quick-reference figure, though real density varies from about 1.35 to 1.7 tons per cubic yard depending on the specific stone type, gradation, and moisture content. This calculator uses 1.4 tons/yd³ as a default, but the field is fully editable — ask your supplier for their specific product's density if you want a tighter estimate, since different aggregates (limestone, granite, river gravel) can weigh noticeably different amounts for the same volume.
Because area is measured in square feet while depth is more naturally specified in inches, the calculator handles that unit conversion internally, computing volume in cubic yards (the unit aggregate suppliers typically quote by) before converting to the final tons figure.
- Enter the area's length and width in feet.
- Enter the planned stone depth in inches.
- Leave the density at the typical 1.4 tons/yd³ default, or enter your supplier's actual product density if known.
- Read the volume in cubic yards and the tons of stone needed.
A 20 x 10 ft garden path, 4 inches deep
A homeowner is laying a 20 ft by 10 ft crushed-stone garden path at a 4 in depth. Volume = 20 x 10 x (4/12) = 66.667 cubic feet, which converts to 66.667/27 = 2.4691 cubic yards. At the typical 1.4 tons/yd³ density: 2.4691 x 1.4 = 3.4568 tons — a small order most landscape suppliers can deliver by the yard or bag.
A larger 50 x 15 ft driveway base at a deeper 6 in, using a denser 1.5 tons/yd³ stone, scales up considerably: volume = 50 x 15 x 0.5 = 375 cubic feet, or 375/27 = 13.8889 cubic yards, giving 13.8889 x 1.5 = 20.8333 tons — roughly six times the path project's tonnage, reflecting the much larger area, greater depth, and denser material all compounding together.
Questions
Why does the density figure matter so much for my order?
Crushed stone density genuinely varies by 25% or more between different stone types and gradations — from around 1.35 to 1.7 tons per cubic yard — so using an inaccurate density can leave your order noticeably short or long compared to what the project actually needs. Ask your specific supplier for their product's density if you want a tighter estimate than the 1.4 tons/yd³ typical default.
How deep should crushed stone be for a driveway base versus a walking path?
Driveway bases that need to support vehicle weight typically use 4-6 inches or more of compacted base material, while decorative walking paths or garden beds often use 2-4 inches. The right depth depends on your specific application, soil conditions, and expected loads — check with a contractor or supplier for your project's requirements.
Does this calculator account for soil compaction under the stone?
No, this calculates the volume and weight of crushed stone to fill the space at your entered depth — it doesn't add material for soil excavation, compaction settling, or any base preparation beneath the stone layer. Some projects lose a bit of depth to settling and may need a small top-up after initial compaction.
Should I order extra stone beyond the calculated amount?
Many suppliers and contractors add a small buffer for compaction settling and to avoid running short mid-project, since crushed stone compacts somewhat once spread and compacted with a plate compactor or roller. This calculator gives the theoretical fill volume at your entered depth; ask your supplier what buffer they typically recommend.