Sand and Gravel Mix Calculator

Blending shrinks the combined volume slightly as sand fills the voids between gravel pieces, and moisture changes both weights. The split below is by loose volume, the way suppliers sell and yards measure.

Last updated: 7 November 2026 · Report an error

The split is simple parts-math: total volume ÷ total parts × each material's share. Worked example: 2 cubic yards of a 1:2 (sand : gravel) blend is 3 parts: sand gets ⅓ → 0.67 yd³ ≈ 0.9 tons, gravel gets ⅔ → 1.33 yd³ ≈ 1.9 tons.

One honest footnote: mixed volumes don't add perfectly — sand migrates into the gravel voids, shrinking the blend a few percent versus the sum of its parts. For ordering, that's well inside the usual 5–10% margin.

There is no single "standard" sand-to-gravel ratio — the right split follows the job. Gravel gives a blend its skeleton: strength, drainage and resistance to movement. Sand fills the voids between stones, which is what lets a blend compact into a tight, stable mass instead of a loose pile that shifts under load. More sand makes a blend finish smoother and cushion softer; more gravel makes it drain faster and carry more.

Two cautions about the table. First, these ratios are by loose volume — bucket or shovel counts, the way the calculator splits them — not by weight, because sand and gravel have different densities (sand ≈ 1.35 t/yd³, gravel ≈ 1.42 t/yd³). Second, a blend is not a graded aggregate: a supplier's engineered base material is screened to a continuous size range, while a site blend of two stockpiles is not. For ordinary bases, bedding and fill that difference rarely matters; for the jobs in the last section of this page, it does.

Paver patio base. A 12 × 10 ft patio on a 4-inch compacted base is 120 ft² × 0.333 ft = 40 ft³ (1.48 yd³) of blend. At 1 : 2 that splits into sand 13.33 ft³ (0.49 yd³ ≈ 0.67 tons) and gravel 26.67 ft³ (0.99 yd³ ≈ 1.40 tons). Because the base gets plate-compacted, order roughly 10% over these figures — call it 0.55 yd³ of sand and 1.1 yd³ of gravel — rather than discovering the shortfall with the compactor already hired.

Pipe bedding. A 40 ft utility trench, 1 ft wide, bedded and covered with 9 inches of blend, takes 40 × 1 × 0.75 = 30 ft³. At the bedding ratio of 2 : 1, that is sand 20 ft³ (0.74 yd³ ≈ 1.00 ton) and gravel 10 ft³ (0.37 yd³ ≈ 0.52 tons). The sand-heavy mix is deliberate: it packs around the pipe haunches without point loads from stone.

General fill. Raising and levelling a low area with 5 yd³ of bank-run style fill at 1 : 1 splits evenly — 2.50 yd³ of sand (≈ 3.37 tons) and 2.50 yd³ of gravel (≈ 3.54 tons). Note the weights differ even though the volumes match: gravel is the denser material, which is why this calculator reports both for every blend.

Every figure above is exactly what the calculator at the top of this page returns for the same inputs — run them and check.

Most yards sell a pre-blended sand-and-gravel — bank run, all-in ballast, or "base material" — at roughly an even or gravel-leaning split. Pre-blended wins on consistency (the ratio is the same in the last shovelful as the first) and on logistics: one delivery, one pile. Mix it yourself when you need an off-standard ratio, when the two materials are already on site, or when the gravel fraction has to be a specific stone — washed drainage gravel, for example, which no pre-blend contains.

Two mixing realities the calculator cannot see. Shrinkage: sand migrates into the voids between gravel pieces, so a finished blend occupies a few percent less volume than its parts measured separately — one reason the standard ordering margin is 5–10%. Damp sand bulks: moist sand occupies noticeably more loose volume than the same sand dry, so a blend measured out with damp sand quietly under-delivers sand once everything dries and settles. Neither effect is large enough to change an order on its own; together they are exactly what the margin is for.

Structural concrete. A two-part blend is not graded aggregate, and blending sand and gravel at a guessed ratio is not a mix design. Anything load-bearing needs the full cement : sand : gravel ratio with controlled water — start from the concrete mix ratio calculator, and for real structural work, a tested design.

Drainage layers and French drains. Sand is the enemy here: it migrates into the stone voids and chokes the flow the drain exists to provide. Drainage wants washed, open-graded stone like #57 with no sand fraction at all — see the French drain calculator.

The bedding layer under pavers. The final 1-inch screed layer pavers actually sit on is pure bedding sand. Gravel particles in that layer telegraph through as bumps and point loads under individual pavers. Blend below, sand on top.

Septic and drain-field work. Fields are built to a specified washed aggregate; a site blend will not meet spec and can fail inspection.

Finished, visible surfaces. A blend compacts grey and dusty and tracks everywhere. Paths and patios people walk on barefoot want a single clean material — pea gravel or a washed decorative stone.