Calculator Form
Example Data Table
| Project | Area | Depth | Waste | Density | Order yd³ | Estimated tons |
|---|---|---|---|---|---|---|
| Garden path | 180 sq ft | 2 in | 8% | 1.35 tons/yd³ | 1.20 | 1.62 |
| Parking pad | 480 sq ft | 4 in | 10% | 1.40 tons/yd³ | 7.82 | 10.95 |
| Drainage trench | 95 sq ft | 6 in | 12% | 1.30 tons/yd³ | 2.16 | 2.81 |
Formula Used
Rectangle area: length × width.
Circle area: π × radius².
Triangle area: 0.5 × base × height.
Trapezoid area: ((top width + bottom width) ÷ 2) × height.
Finished cubic feet: area in square feet × depth in feet.
Finished cubic yards: finished cubic feet ÷ 27.
Order cubic yards: finished cubic yards × compaction factor × waste factor.
Tons: order cubic yards × rock density in tons per cubic yard.
Bags: ceiling((tons × 2,000) ÷ bag weight).
Confidence range: expected amount ± z-score × variability percentage.
How to Use This Calculator
- Select the project shape or choose custom area.
- Enter the matching dimensions and unit.
- Add the finished rock depth.
- Enter density from your supplier when known.
- Add compaction, waste, cost, delivery, tax, and bag settings.
- Choose a confidence level for a wider or narrower planning range.
- Press the calculate button.
- Review yardage, tons, bags, cost, chart, and download options.
Crushed Rock Yardage Planning Guide
Why Yardage Accuracy Matters
Crushed rock is dense, costly, and hard to move twice. A small depth error can change a truck order. This calculator turns surface dimensions into cubic yards, tons, bags, cost, and delivery load estimates. It also adds compaction and waste, because finished beds rarely match textbook volumes.
Plan the Surface First
Start with the real shape of the work area. Use rectangle for driveways, circle for tree rings, triangle for corners, trapezoid for tapered paths, or custom area when you already know square footage. Measure in one unit when possible. Rounded edges and curves should be split into simple sections. Add each section later, or run separate estimates.
Depth Controls the Order
Depth is the biggest driver after area. A thin decorative layer may need two inches. A walkway base may need four inches. A driveway base can need more, over soft soil. Enter the finished depth you want after spreading. Then use compaction percentage to account for settling, rolling, or plate compaction.
Density, Tons, and Bags
Crushed rock is often ordered by cubic yard or ton. Density changes by stone size, moisture, and quarry source. The default density is a practical planning value, not a lab test. Use your supplier value when available. Bag estimates are useful for small jobs. Bulk tons are usually better for larger areas.
Cost and Delivery Planning
The calculator separates material cost, delivery fee, and tax. It also estimates truckloads from truck capacity. This helps compare bag pickup, bulk delivery, and full truck delivery. Add waste for edges, uneven subgrade, spillage, and touch ups.
Use the Statistical Range
The confidence range is a planning tool. It applies a variability percentage to expected tonnage. A higher confidence level gives a wider upper estimate. Use it when the surface is uneven, measurements are rough, or stone density is uncertain. It is not a guarantee. It is a safer ordering guide.
Better Final Checks
Before ordering, confirm the supplier density, minimum delivery, and truck access. Check slope and drainage. Mark utilities. Spread rock in layers when depth is high. Recheck measurements. Good estimates reduce shortages, returns, delays, and extra handling on site today.
FAQs
1. What is a cubic yard of crushed rock?
A cubic yard is a volume measuring 3 feet long, 3 feet wide, and 3 feet deep. It equals 27 cubic feet.
2. How many tons are in one cubic yard?
Many crushed rocks weigh about 1.2 to 1.5 tons per cubic yard. Actual weight depends on stone type, size, moisture, and supplier density.
3. Should I add waste allowance?
Yes. Add waste for spillage, uneven ground, edge loss, and measurement error. Many small projects use 5% to 12% waste.
4. What depth should I use?
Decorative rock may need 2 inches. Paths often need 3 to 4 inches. Driveway bases may need deeper layers.
5. Why include compaction?
Rock can settle after spreading or compacting. A compaction allowance helps estimate loose material needed to reach the final compacted depth.
6. Are bag estimates exact?
Bag estimates are rounded up. Bag weights and fill volumes can vary, so check the label before buying.
7. What does the confidence range mean?
It shows a low and high planning estimate based on your variability setting. Higher confidence creates a wider safety range.
8. Can I use this for gravel?
Yes. You can use it for gravel, crushed stone, road base, drainage rock, and similar aggregate materials.