Project and geometry
Sample base course takeoff table
| Item | Shape | Plan dimensions | Thickness | Layers | Delivered volume (m³) | Delivered tons (t) |
|---|---|---|---|---|---|---|
| Access Road | Rectangle | 120 m × 7.5 m | 150 mm | 1 | 148.500 | 237.600 |
| Yard Pad | Circle | Diameter 18 m | 200 mm | 1 | 67.200 | 107.520 |
| Shoulder Widening | Trapezoid | 80 m; 6.0 m to 8.0 m | 120 mm | 2 | 203.808 | 326.093 |
How the calculator works
- Rectangle: A = L × W
- Trapezoid (two widths): A = ((a + b) ÷ 2) × L
- Circle: A = π × (D ÷ 2)²
- Custom: use your known takeoff area
- Delivered tons: T = Vl × density
- Cost (per m³): Cost = Vl × rate
- Cost (per ton): Cost = T × rate
Step-by-step
- Select a plan unit, then choose your shape.
- Enter plan dimensions or your known area.
- Enter compacted thickness and number of layers.
- Add waste allowance and a loose factor, if applicable.
- Select a density preset or enter a custom density.
- Optional: enter a rate and pricing basis for cost.
- Press Calculate, then export CSV or PDF.
Base course volume estimating for construction work
A base course is the engineered granular layer placed beneath asphalt, concrete, or pavers to provide stiffness, drainage, and a uniform platform for compaction. Accurate quantity takeoff reduces haulage risk, prevents material shortages, and improves bid pricing. This calculator converts your plan geometry and specified compacted thickness into a compacted volume, then applies practical field adjustments such as waste allowance and a loose factor for delivery. The result is presented in cubic meters and cubic yards, with optional tonnage and cost estimates.
Start by selecting the correct shape. Rectangles are common for roads, slabs, and storage yards. Trapezoids are useful for widening, shoulders, or transitions where the width changes along the length. Circular pads apply to tank foundations and round storage areas. If you already have a measured area from a survey or CAD takeoff, choose custom area and focus on thickness, layers, and factors. For thickness, enter the compacted layer thickness, then set the number of layers to match your specification.
The two most important adjustments are waste and loose factor. Waste covers trimming, edge loss, spreading variation, and minor rework. Loose factor converts compacted demand into a delivered quantity because aggregates are supplied in a looser state than their compacted condition. Typical loose factors range from 1.05 to 1.20, but moisture, gradation, and equipment can shift this value. When in doubt, verify the supplier’s conversion or check your project’s method statement.
Weight and cost outputs depend on density and pricing basis. Density varies by material type and moisture; use a laboratory value, a supplier ticket conversion, or a project standard. If your supplier quotes per ton, the calculator multiplies delivered volume by density to estimate tonnage and cost. If your quote is per delivered cubic meter, cost is computed directly from delivered volume. Treat cost results as planning figures and confirm unit rates, haul distance, and compaction requirements during procurement.
Worked example: For the sample “Access Road” (120 m × 7.5 m) at 150 mm thickness, one layer, 5% waste, and a 1.10 loose factor, the compacted volume is 135.000 m³. After waste and loose factor, delivered quantity becomes 155.925 m³. Using 1.60 t/m³ density, delivered weight is about 249.480 t. Use these outputs to plan trucks, stockpile space, and daily production targets.
Frequently asked questions
1) Should I enter loose thickness or compacted thickness?
Enter compacted thickness. The loose factor then converts compacted demand to delivered volume, which better matches supplier quantities and field reality.
2) What loose factor should I use for base course?
Common values are 1.05–1.20. Use a value from your specification, supplier conversion, or past site records. Moisture and gradation can change the factor.
3) How do I choose a waste percentage?
Use 3–10% for most granular base work. Higher allowances may be needed for tight grading tolerances, complex edges, or areas with frequent rework.
4) Can I price per ton and still see cubic meters?
Yes. The calculator shows volumes first, then converts delivered volume to tons using density. Select “Per ton” to apply your unit rate correctly.
5) Why does delivered volume differ from compacted volume?
Delivered material is loose and contains voids. Compaction reduces voids and increases density, so you must order more volume than the compacted volume requires.
6) What density value is appropriate for aggregates?
Typical planning values range from 1.55 to 2.10 t/m³ depending on material and moisture. For best accuracy, use lab-tested density or supplier ticket conversions.
7) How can I validate the calculator results onsite?
Compare ordered quantity to truck tickets, measure placed thickness and area, and back-calculate volume. Adjust waste and loose factor until estimates match your production data.