#57 Stone Calculator: Tons and Cubic Yards
Calculate crushed stone #57 (3/4″) volume and tonnage for French drains, driveway sub-bases, and drainage projects. Defaults to 1.40 ton/yd³ (practical ordering density) — confirm with your supplier.
#57 stone is one of those materials that looks simple on the spec sheet until you realize the "ordering density" your supplier bills at can differ from the lab number by enough to throw off a large order. Knowing which number to use — and why — keeps your invoice from surprising you.
Crushed stone #57 is the workhorse drainage aggregate: angular 3/4″ particles that nest together loosely without compacting, letting water flow freely through the voids. It is the standard choice for French drains, under-slab drainage, driveway sub-base, and concrete aggregate.
Important density note: The calculator defaults to 1.40 ton/yd³ — the practical ordering density most suppliers bill at (typical range 1.4–1.5 ton/yd³). Loose/lab dry density is a bit lower (~1.35 ton/yd³). Defaulting to the ordering figure means estimates don't fall short; always confirm exact density with your supplier and add a 10–15% waste allowance.
Project Dimensions
How the math works
Step 1 — volume in cubic yards
cu yd = (length_ft × width_ft × depth_in) ÷ 324 324 = 27 cu ft/yd × 12 in/ft. A canonical landscaping shortcut: multiply area by depth (in inches) and divide by 324.
Step 2 — apply waste / compaction allowance
cu yd (with waste) = cu yd × (1 + waste % ÷ 100) The waste allowance inflates both tonnage and bag count — you buy the waste-inclusive amount.
Step 3 — tons
tons = cu yd × density (ton/yd³) Material densities (US short tons per cubic yard): pea gravel 1.35, #57 stone 1.40, paver base 1.40, river rock 1.30, crusher run 1.40. Confirm exact weight with your supplier — density varies with moisture and stone source.
Step 4 — retail bags
bags = ⌈ cu yd × 54 ⌉ A standard 50 lb bag holds 0.5 cu ft. One cubic yard = 27 cu ft ÷ 0.5 = 54 bags.
How #57 stone differs from other gravel
Unlike paver base or crusher run, #57 does not compact — there are no fines to fill the voids and lock the particles. That is a feature for drainage applications but a liability if you need a stable compacted layer. For a patio sub-base or shed pad, use paver base (3/8″ minus dense-grade) or crusher run instead.
For driveways, a common three-layer approach is: 6 in of crusher run base (compacted), 4 in of #57 base course, then 2 in of pea gravel or paver base as the wearing surface. Use the driveway calculator to size all three layers.
Sources
- Inch Calculator — Gravel Calculator: #57 stone density (1.40 ton/yd³ practical ordering range 1.4–1.5) and volume formula.
- Machinery Partner — Crushed Stone Grades Guide: #57 stone size classification and drainage application guidance.
Frequently Asked Questions
The calculator defaults to 1.40 ton/yd³ — the practical ordering density most suppliers bill at (typical range 1.4–1.5 ton/yd³), and within the published range (1.21–1.50 ton/yd³). Loose/lab dry density is a bit lower (~1.35 ton/yd³). Always confirm the exact density with your supplier and add 10–15% margin when ordering.
#57 crushed stone (3/4") is used for French drains and drainage channels, driveway sub-bases, concrete aggregate, under-slab fill, and septic-system drain fields. Its open-graded structure means it drains freely and does not compact under load.
No — #57 is open-graded, meaning the angular particles leave voids and the stone does not bind together. It drains freely but will not support a compacted sub-base. For a compacted base, use paver base or crusher run instead.
A standard French drain uses 6–12 in of #57 stone surrounding a perforated pipe. For a simple surface drain channel without pipe, 6 in is typical. Use the 10–15% waste allowance for trench work.
The calculator uses 1.40 ton/yd³ — the practical ordering density most suppliers bill at (typical range 1.4–1.5 ton/yd³). This aligns with what you will actually be charged per ton. Loose/lab dry density is ~1.35 ton/yd³. If your supplier quotes a different density, adjust your order accordingly.