THE MATH, MADE VISIBLE
How it works
Area × loose layer depth = base volume. Add your allowance once. Divide cubic feet by 27 for cubic yards. Weight is volume × supplier bulk density; a US short ton is 2,000 lb.
Real project examples
A small path
12 × 9 ft at 3 in deep = 27 ft³. With 10% extra, order 29.7 ft³ (1.10 yd³). At 0.5 ft³ per bag, buy 60 bags.
A round bed
A 10 ft diameter circle at 3 in deep needs 19.63 ft³ before any allowance. At 100 lb/ft³ supplier density, that is about 0.98 US short tons.
Before you buy
- Ask the supplier whether the quote is per cubic yard, US short ton or metric tonne. These units are not interchangeable.
- Density changes with grading, moisture and packing. Use the density of your actual product; leave it blank if unknown.
- This is a loose-volume estimate. If you measured a compacted layer, ask the supplier for a loose-to-compacted order factor rather than treating waste as compaction.
Questions worth asking
Can I convert cubic yards directly to tons?
Only with bulk density. One cubic yard is 27 cubic feet, but its weight depends on your stone and its condition.
Why is the bag count rounded up?
Stores sell whole bags. We show the allowance before rounding so you can distinguish your project buffer from the package rounding.
Does this estimate a driveway structure?
No. Determine layer material, thickness and compaction requirements separately; then calculate each material layer.
Sources & assumptions
NIST · unit conversion factorsVulcan Materials · aggregate estimatorLast reviewed October 1, 2026. Planning defaults are editable examples. Product labels and supplier information override them.