Crushed Stone Calculator — #57, #8, #4, 3/4"
"Crushed stone" covers a family of products graded by size, all angular and roughly the same weight per cubic yard. The two numbers you'll trip on:
- Stone number = stone size. #57 = ~3/4 inch. #8 = ~3/8 inch. #4 = ~1.5 to 2.5 inch. Higher number, smaller stone (mostly).
- Density variations are small. All crushed stone in this family weighs 2,650–2,750 lb per cubic yard. The calculator picks the right average for the grade you select.
- #57: driveways, drainage, French drains — the all-purpose default.
- #8: paver bedding, fine surfaces, finishing layer.
- #4: deep base layers under driveways, erosion control, very heavy traffic.
- Crushed limestone: driveways and sub-bases in regions where it's the local stone.
"Washed" vs "unwashed" matters for drainage projects — washed stone has the dust rinsed off and is what you want for French drains and around perforated pipe. For driveway top course, unwashed (cheaper) is fine.
Recommended depth & material
| Use | Depth | Material | Notes |
|---|---|---|---|
| Driveway top course | 2" | #57 unwashed | Over a compacted base. |
| Driveway combined depth (refresh) | 4" | #57 | If skipping a separate base layer. |
| Driveway base (under top course) | 4" | #4 (deep) or ABC base | Then #57 on top. |
| French drain / drainage | 12" | #57 washed | Washed only — dust clogs the pipe. |
| Paver bedding | 1" – 2" | #8 stone | Or coarse concrete sand for finer setting bed. |
| Patio base | 4" | #57 | Or CA6 if pavers go on top. |
Crushed Stone Calculator — #57, #8, 3/4"
Crushed stone is sold by the ton — your measurement should land you within a half-ton of the right order. The calculator handles the rest.
- Pick your grade. Filter the material picker to the right stone number — #57 for general use, #8 for fine work, #4 for deep base layers. Crushed limestone is its own product (similar density to #57).
- Measure length × width. In feet, for the area you're filling. Use multi-area mode for irregular shapes.
- Set depth in inches. Use the depth presets if you're unsure. 4" is the all-purpose default for driveway/patio work.
- Specify washed if needed. Washed stone costs ~10% more but is mandatory for French drains, drainage projects, and any application where stone dust would clog something downstream.
- Add 10–15% buffer. 10% for clean rectangular jobs. 15% for trenches, slopes, or irregular shapes where the perimeter takes more material than the math says.
- Order in tons (US). Crushed stone is sold per ton at almost every quarry in North America. Confirm whether the price is delivered or picked-up before ordering.
Worked example: 200 sq ft of #57 stone, 4" deep
A 200 sq ft area — say a 10' × 20' parking pad or a 200 sq ft path:
- Volume: 200 × 4 ÷ 324 = 2.47 yd³
- Weight: 2.47 × 2,750 ÷ 2,000 = 3.4 tons
- With 10% buffer: ~3.7 tons of #57.
- Cost: at $40/ton (typical for #57 in many US markets), ~$148 in stone, plus an $80–$150 delivery fee.
Same area in #8 (smaller stone, slightly lower density) would come to about 3.3 tons. Same area in #4 (larger, denser): about 3.3 tons. The differences between grades are small at typical depths — the depth and area are the variables that move the order.