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 |
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.
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 |