Calculator Inputs
Plotly Graph
The chart compares compacted volume, loose order volume, total tons, and truck loads from your latest calculation.
Example Data Table
| Project | Shape | Plan Size | Depth | Density | Waste | Compaction | Loose Volume | Tons |
|---|---|---|---|---|---|---|---|---|
| Residential Driveway | Rectangle | 20 m × 4 m | 150 mm | 2.10 t/m³ | 5% | 1.18 | 14.87 m³ | 31.23 |
| Parking Pad | Rectangle | 15 m × 8 m | 180 mm | 2.10 t/m³ | 4% | 1.20 | 26.96 m³ | 56.62 |
| Access Road | Rectangle | 45 m × 6 m | 200 mm | 2.05 t/m³ | 5% | 1.15 | 65.21 m³ | 133.68 |
Formula Used
1) Area
Rectangle: Area = Length × Width
Circle: Area = π × Radius²
Triangle: Area = 0.5 × Base × Height
Trapezoid: Area = ((Top Width + Bottom Width) ÷ 2) × Length
2) Compacted Volume
Compacted Volume = Area × Compacted Depth
3) Loose Volume to Order
Loose Volume = Compacted Volume × Compaction Factor × (1 + Waste % ÷ 100)
4) Total Weight
Total Tons = Loose Volume × Bulk Density
5) Truck Loads
Truck Loads = Required Quantity ÷ Capacity per Load
6) Cost
Estimated Cost = Quantity × Unit Cost
How to Use This Calculator
- Select the area shape that best matches the road base section.
- Enter plan dimensions using meters, feet, or yards.
- Enter compacted depth in millimeters, centimeters, meters, inches, or feet.
- Add bulk density from your supplier or specification sheet.
- Set the compaction factor to reflect how loose aggregate expands before placement.
- Include a waste allowance for trimming, spillage, and uneven subgrade conditions.
- Choose truck capacity and cost basis for delivery and budgeting.
- Press Calculate Road Base to view area, volume, tonnage, loads, cost, and the graph above the form.
Frequently Asked Questions
1. What is road base material?
Road base is a compacted aggregate layer placed under asphalt, pavers, or concrete. It supports loads, improves drainage, spreads pressure, and reduces settlement in driveways, roads, parking pads, and paths.
2. Why does the calculator use a compaction factor?
Loose aggregate occupies more space before rolling and compaction. The compaction factor converts final compacted volume into the larger loose quantity you usually need to order from a supplier.
3. Should I calculate by tons or by cubic volume?
Use the same basis your supplier uses for pricing and delivery. Many quarries sell by ton, while some local suppliers quote by cubic yard or cubic meter.
4. What density should I enter?
Use your supplier’s stated bulk density whenever possible. Crushed stone and road base blends often vary with moisture, gradation, and source, so one universal density is not always accurate.
5. How much waste allowance is typical?
A waste allowance of 3% to 8% is common for many projects. Larger sites, irregular shapes, soft subgrades, or hand-spread work may justify higher allowances.
6. Can this calculator work for driveways and parking areas?
Yes. It works for roads, lanes, shoulders, parking pads, driveways, patios, storage areas, and other aggregate base applications where you know area, depth, density, and order conditions.
7. Why are loose volume and compacted volume different?
Compacted volume is the finished in-place quantity. Loose volume is the delivered quantity before rolling. Because voids shrink during compaction, the loose amount must be greater.
8. Can I use the truck loads result for scheduling deliveries?
Yes, but round up to whole loads and confirm axle limits, truck body size, route restrictions, and supplier loading practices. Field conditions can also change actual delivery count.