Material reference
The densities, coverage rates, waste allowances and national-average prices behind every calculator. Physical constants are standard engineering values; prices are 2026 seed estimates shown as ranges.
| MATERIAL | KEY CONSTANT | WASTE | PRIMARY UNIT & PRICE |
|---|---|---|---|
| Ready-mix concrete | 145 lb/ft³ | 7% | $125–$165 cubic yards (ready-mix) |
| Gravel / crushed stone | 1.4 tons/yd³ | 5% | $40–$65 tons |
| Sand (paver / leveling) | 1.35 tons/yd³ | 5% | $30–$55 tons |
| Topsoil | 1.1 tons/yd³ | 5% | $25–$50 cubic yards (bulk) |
| Mulch | 108 ft²/yd³ @ 3″ | 5% | $30–$50 cubic yards (bulk) |
| Hot-mix asphalt | 145 lb/ft³ | 5% | $100–$160 tons (hot-mix) |
| Drywall (gypsum board) | — | 10% | $11–$18 4x8 sheets (32 ft²) |
| Interior/exterior paint | 350 ft²/gal/coat | 0% | $28–$60 gallons |
| Floor/wall tile | — | 12% | $18–$70 boxes |
| Concrete pavers | — | 10% | $0.4–$1.5 pavers (4"x8") |
| Deck boards | — | 10% | $1.75–$6 linear feet of decking |
| Wood privacy fence | — | 5% | $2.5–$6 pickets (6 ft) |
| Rebar (#4, 1/2 in) | — | 10% | $0.65–$1.6 linear feet of #4 rebar |
| Retaining wall block | — | 5% | $2.5–$8 wall blocks |
Sources
- Concrete density 145 lb/ft^3 and bag yields: Portland Cement Association / bag manufacturer spec sheets (Quikrete/Sakrete)
- Aggregate densities ~1.4 tons/yd^3: US Army Corps / standard aggregate references
- Mulch coverage 1 yd^3 = 108 ft^2 @ 3 in: horticultural standard
- Paint coverage 350 ft^2/gal/coat: manufacturer spec (Sherwin-Williams/Behr)
- Prices: national-average seed estimates; refresh from supplier quotes / Producer Price Index (BLS series WPU13)