About this tool Calculate asphalt tonnage for surfacing, binder, and base course layers. Select from 7 common UK asphalt mixes — AC 10, AC 14, AC 20, AC 32, SMA 10, SMA 14, and HRA 30/14 — each with their compacted density.
Enter the length, width, and layer thickness to get the net weight in tonnes and an order weight including a 5% waste allowance (lower than concrete because asphalt is typically machine-laid with less spillage).
The mix descriptions include typical layer thicknesses and applications to help you select the right mix for your project — from thin surface courses for car parks to heavy-duty base courses for trunk roads.
How to use this tool 1. Select the asphalt mix — choose based on the layer type (surface, binder, or base) and application.
2. Enter dimensions — length and width in metres, layer thickness in millimetres.
3. Read the results — use the order weight (including 5% waste) when placing your asphalt order.
Technical information Weight (t) = length × width × (thickness / 1000) × density / 1000
Densities: AC surface courses 2,350 kg/m³, AC binder/base courses 2,400 kg/m³, SMA 2,350 kg/m³, HRA 2,300 kg/m³. These are compacted densities per BS EN 13108 series.
Limitations Densities are typical values for standard mix designs. Actual density depends on aggregate type, binder content, and air void content. Confirm with your supplier's mix design data for critical quantities.
The 5% waste allowance is for machine-laid asphalt. For hand-laid patches or irregular areas, increase the allowance to 10-15%.
This tool calculates a single layer. For multi-layer construction (e.g. base + binder + surface), run the calculator separately for each layer.
Revision history 21 April 2026: Initial release
Disclaimer This tool is provided for educational and general information purposes only. It is not a substitute for professional engineering advice, design or verification.
Diggy and its contributors are not licensed engineering consultants and no results generated by this tool should be used directly for construction, design or safety-critical decisions.
All values and outputs are based on published empirical correlations and should be independently checked and confirmed by a qualified geotechnical engineer before use.
By using this tool, you accept full responsibility for how you interpret and apply the information provided.
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