Why GravelGenie exists
Ordering gravel should not require a spreadsheet or a call to a contractor friend. Yet most people either guess and come up short — paying a second delivery fee and getting a mismatched batch — or over-order and leave a pile of stone in the driveway for a year. GravelGenie turns three measurements into an order-ready figure in seconds, and explains the reasoning so you can trust it. Every calculator is free, needs no sign-up, and works on your phone at the supplier’s yard.
How we calculate — the method
All of our tools run one tested calculation engine, so the home gravel calculator, the driveway and pea gravel tools always agree. The math is deliberately transparent:
- Volume = area × depth, worked in feet, then divided by 27 for cubic yards.
- Weight = cubic yards × the stone’s bulk density (below).
- Bags = cubic feet ÷ 0.5 (the common half-cubic-foot, ~50-lb bag).
- Waste = a default 10% added for settling, compaction and spillage.
We round only at the end, for display — never mid-calculation — so the tons and yards stay consistent with each other.
The density figures we use
Converting volume to weight needs a bulk density, and gravel’s density varies with stone size, angularity and moisture. We use conservative mid-range values from industry aggregate tables and supplier spec sheets, and we publish them here so nothing is hidden:
| Gravel type | Density (t/yd³) |
|---|---|
| Standard / #57 gravel | 1.40 |
| Crushed stone / crusher run | 1.40 |
| River rock | 1.40 |
| Pea gravel | 1.35 |
| Crushed limestone | 1.35 |
Dry gravel typically weighs 2,700–3,000 lb per cubic yard (about 1.35–1.50 tons), and wet stone can weigh 10–15% more. Because your supplier’s exact stone may differ, we treat these as reliable planning figures and always recommend confirming final tonnage with the yard before you order.
Our commitment to accuracy
A wrong number here costs you real money at the yard, so accuracy is the whole point. If you ever get a result that looks off, or you have a better density figure for a specific stone, we want to hear it — contact us and we will check and correct it. Estimates from GravelGenie are guidance to plan and budget with, not a substitute for your supplier’s measured quantities.