How volume and weight are calculated
Gravel, mulch, topsoil, and sand are sold by the cubic yard but weigh very different amounts per yard. Volume in cubic feet is length × width × depth (converted to feet), divided by 27 for cubic yards. Weight is an estimate: cubic yards × the material's typical density in tons per yard.
Approximate density by material
| Material | Tons per cubic yard |
|---|---|
| Gravel / crushed stone | ~1.4 |
| Sand | ~1.5 |
| Topsoil | ~1.2 |
| Mulch | ~0.4–0.6 |
Related guides
Frequently asked questions
How much should I add for compaction?
For gravel used as a base layer, many contractors add 10–15% extra volume to account for compaction depth loss after tamping.
Can I use this for a circular bed?
Yes — find the area of the circle first (π × radius²), then enter an equivalent rectangle with the same area.
Planning gravel, mulch or topsoil
Bulk-material estimates start with area × depth to obtain volume. The calculator converts that volume into cubic yards and can provide an approximate weight. Weight varies substantially with material type, moisture and supplier, so the tonnage figure is a planning estimate.
Depth is the key input
A small change in depth can have a large effect on the amount required. Measure the intended finished depth and use the same unit for length and width. For an irregular area, split the space into simple sections and add the volumes.
Volume versus weight
Two cubic yards of different materials can weigh very different amounts. Gravel, mulch and topsoil have different bulk densities, and moisture can change the weight again. For delivery, confirm the supplier's density or quoted weight limits.
Ordering with a margin
Material can be lost to uneven ground, settling, spillage or small measurement errors. A sensible allowance reduces the chance of running short, but the right percentage depends on the project and material.