Asphalt Quantity Calculator
Get an order-ready asphalt quantity figure — not just a theoretical calculation, but a number that accounts for real-world waste and handling loss.
Asphalt Quantity Calculator
Dimensions
Mix Properties
Typical Bitumen Content by Mix Type
| Mix Type | Bitumen |
|---|---|
| General Asphalt | 5.0% - 5.5% |
| High Traffic Roads | 6.0% - 7.0% |
| Rigid Pavements | 4.0% - 4.5% |
| Binder Courses | 4.5% - 5.5% |
| Wearing Courses | 5.5% - 6.5% |
| Stone Mastic Asphalt | 6.5% - 7.5% |
There’s a difference between the theoretical asphalt quantity a project needs (based purely on geometry and density) and the quantity you should actually order. This calculator gives you the theoretical figure directly; this page walks through how to adjust it into an order-ready number.
From theoretical quantity to order quantity
Order quantity
Order Quantity = Calculated Quantity × (1 + Waste Allowance %)
A 5–10% waste allowance is standard for most paving jobs; see our full waste percentage guide for how to pick the right figure for your specific project.
| Job Type | Recommended Waste Allowance |
|---|---|
| Large, simple rectangular area | 5% |
| Standard driveway or small commercial job | 7–10% |
| Irregular shape with many edges/obstacles | 10–15% |
| Small patch or repair | 15–20% |
Why quantity estimates commonly go wrong
- Using loose (uncompacted) thickness instead of the specified compacted thickness
- Forgetting to convert thickness from millimeters to meters before calculating volume
- Using a generic density figure instead of the supplier’s actual mix density
- Not adding any waste allowance, then running short mid-project
Worked example
Calculated quantity: 47 tonnes. Applying an 8% waste allowance: 47 × 1.08 = 50.76 tonnes — round up to 51 tonnes for the actual order.
Splitting the order between bitumen and aggregate suppliers
If you’re sourcing bitumen and aggregate separately (rather than ordering finished asphalt mix from a plant), this calculator’s output already splits your total quantity into bitumen weight and aggregate weight, so you can place two accurate, separate orders from a single set of project inputs.
This is a common and useful practice, but it only works reliably if you’re confident in the assumed thickness and density on both sides of the comparison — if either figure is a rough guess rather than a confirmed spec value, treat any gap between your estimate and a quote as inconclusive rather than a sign of overcharging.
Multi-layer projects: calculate each course separately
Roads and heavy-duty pavements are rarely a single layer — a typical structure includes a base course, a binder course, and a wearing course, each with its own thickness and sometimes its own mix design and bitumen content. Run this calculator once per layer with that layer’s specific thickness and density, then sum the resulting quantities across all layers for your total project order. Combining layers into a single average thickness calculation understates the material needed whenever layer densities or bitumen contents differ.
See the full waste allowance guide before finalizing your order