Landscape materials are sold in a confusing mix of units: cubic yards for mulch and soil, tons for stone, and bags of every size. Everything starts from the same volume calculation.
Volume first
volume = area × depth. Convert depth to feet before multiplying, then divide cubic feet by 27 to get cubic yards.
Weight from volume
| Material | Approx. density |
|---|---|
| Crushed stone / gravel | 1.3–1.5 tons/cu yd |
| Sand (dry) | 1.3–1.4 tons/cu yd |
| Topsoil | 1.0–1.2 tons/cu yd |
| Road base / crusher run | 1.7–1.9 tons/cu yd |
| Mulch | ~0.3–0.5 tons/cu yd |
Wet material is heavier, often by 10–20%.
What a yard covers
One cubic yard covers 324 sq ft at 1", 162 sq ft at 2", 108 sq ft at 3" and 81 sq ft at 4".
Bags vs bulk
A cubic yard is 13.5 bags of 2 cu ft mulch, or about 54 bags of 0.5 cu ft gravel. Bulk is almost always cheaper above a yard or two, if you have somewhere to drop it.
Compaction and settling
Base materials compact by 15–25%, and loose soil settles 15–20%. Add these allowances to the volume, or you'll come up short.
This guide is general information for estimating. It is not engineering, legal or tax advice. Check local codes and your inspector for your project.