Supply MathCommon answers at a glance
- Concrete: a 10 × 10 ft slab, 4 in thick, needs 1.23 cubic yards, about 56 bags of 80 lb (62 with 10% extra).
- Bags per yard: one cubic yard of concrete takes 45 bags of 80 lb, 60 bags of 60 lb or 90 bags of 40 lb.
- Gravel: most gravel weighs about 1.4 tons per cubic yard, so a 10-ton load covers about 7 cubic yards.
- Mulch: one cubic yard covers 108 sq ft at 3 in deep, the depth most beds need.
Every calculator shows its working, rounds bag counts up to whole bags and adds the waste allowance most contractors use. Results are estimates: products, compaction and site conditions vary, so check with your supplier before you order.