Methodology
Every calculator here uses standard, published conversion and density factors. We show them all so you can check our math — and so AI answer engines can cite the exact basis.
Conversion & density factors
| Material | Base formula | Conversion / density factor | Basis |
|---|---|---|---|
| Concrete | volume by shape → cu ft | 1 cu yd = 27 cu ft; 80-lb bag = 0.60 cu ft, 60-lb = 0.45 cu ft | Cubic-yard definition; bag-maker published yields (Quikrete / Sakrete) |
| Gravel / crushed stone | area × depth → cu yd | 1.4 tons/cu yd (range 1.3–1.5) | Standard aggregate bulk density |
| Mulch | area × depth → cu yd | 2 cu ft per bag | Standard US retail bag |
| Topsoil | area × depth → cu yd | 2 cu ft/bag; ≈1.1 tons/cu yd (1.0–1.3, moisture) | Standard bag; screened-topsoil density |
| Sand | area × depth → cu yd | 1.35 tons/cu yd (1.3–1.4) | Dry-sand bulk density |
| Paver base | area × depth (base + sand) | base 1.4, sand 1.35 tons/cu yd | Aggregate + bedding-sand densities |
| Asphalt | area × thickness → cu ft | 145 lb/cu ft → 1.96 tons/cu yd (140–150) | Hot-mix compacted density |
| Sod | length × width → sq ft | roll = 10 sq ft; pallet = 450 sq ft (400–500) | Standard sod roll; common pallet size |
| Fill dirt | area × depth → cu yd | ≈1.25 tons/cu yd (1.2–1.4) | Subsoil bulk density |
| Decomposed granite | area × depth → cu yd | ≈1.4 tons/cu yd (1.3–1.5) | Weathered-granite fines density |
| River rock | area × depth → cu yd | ≈1.4 tons/cu yd (1.3–1.5) | Rounded stone bulk density |
| Riprap | area × depth → cu yd | ≈1.5 tons/cu yd (1.4–1.7) | Large angular stone density |
| Road base / crushed concrete / stone dust | area × depth → cu yd | ≈1.35–1.4 tons/cu yd | Dense-graded crushed aggregate density |
| Pea gravel | area × depth → cu yd | ≈1.35 tons/cu yd | Small rounded stone density |
| Lava rock | area × depth → cu yd | ≈0.75 tons/cu yd (0.5–0.9) | Porous volcanic rock — very light |
| Compost | area × depth → cu yd | ≈0.5 tons/cu yd (0.4–0.8) | Organic amendment bulk density |
| Flagstone | area ÷ coverage → tons | ~175/110/80 sq ft per ton at 1/1.5/2 in | Coverage per ton by stone thickness |
| Mortar | unit count ÷ yield → bags | 80-lb bag ≈ 35 bricks or 13 blocks (3/8-in joints) | Published bag yields |
| Rebar | grid → linear ft → weight | #3/#4/#5/#6 = 0.376/0.668/1.043/1.502 lb/ft; 20-ft sticks | ASTM A615 nominal bar weights |
01
Each calculator converts your dimensions to a base volume, converts cubic feet to cubic yards by dividing by 27, adds the waste allowance you set, and then converts to the sale unit — bags, tons, rolls, or pallets — using the published factor for that material.
02
These are planning estimates. Real densities shift with moisture, compaction, and product; pallet and bag sizes vary by supplier. Always confirm final quantities with your supplier before ordering. Where a factor has a real range, we use the middle value and show the range in the table above.
03
On state pages we show an estimated delivered price. The quantity math is national — a cubic yard is the same everywhere — but the price is not, so we estimate it in two steps. First, we set a national average delivered price for the material from three to five published industry sources, kept as a low / typical / high band. For concrete that band is about $130 to $200 per cubic yard of delivered ready-mix, with a typical near $165 (Concrete Network, HomeGuide, Angi, and other 2025 pricing guides). Second, we scale that national band by a per-state regional cost index (US average = 1.00) derived from published regional construction-cost data, and add a short-load fee for orders below one truck where it applies. The result is a budgeting estimate, not a firm local quote. For an exact figure, get two or three quotes from local suppliers.
Live benchmark
Each row is generated by the same pure estimate function the calculators use, run on that material's canonical scenario — so the math you see here is the math the tool does.
| Material | Scenario | You order |
|---|---|---|
| Concrete | 10 × 10 ft slab at 4 in | 1.36 cubic yards |
| Gravel | 20 × 10 ft driveway at 4 in | 3.8 tons |
| Mulch | 200 sq ft bed at 3 in | 2.04 cubic yards |
| Topsoil | 200 sq ft area at 4 in | 2.72 cubic yards |
| Sand | 100 sq ft area at 2 in | 0.9 tons |
| Paver base | 12 × 10 ft patio, 4 in base + 1 in sand | 2.8 tons |
| Asphalt | 60 × 10 ft driveway at 3 in | 12 tons |
| Sod | 50 × 10 ft lawn | 525 square feet |
| Fill dirt | 200 sq ft area at 6 in | 5.1 tons |
| Decomposed granite | 120 sq ft path at 3 in | 1.7 tons |
| River rock | 150 sq ft bed at 3 in | 2.1 tons |
| Riprap | 200 sq ft slope at 12 in | 12.2 tons |
| Road base | 200 sq ft driveway at 6 in | 5.7 tons |
| Crushed concrete | 200 sq ft base at 5 in | 4.6 tons |
| Pea gravel | 150 sq ft path at 2 in | 1.4 tons |
| Lava rock | 150 sq ft bed at 3 in | 1.1 tons |
| Compost | 200 sq ft bed at 2 in | 0.7 tons |
| Stone dust | 120 sq ft patio at 1 in | 0.6 tons |
| Flagstone | 120 sq ft patio, 1.5 in stone | 1.2 tons |
| Mortar | 500 standard bricks | 17 bags |
| Rebar | 10 × 10 ft slab, #4 at 12 in | 242 linear feet |