Aggregate Base Coverage Calculator

How the aggregate base coverage calculator works

This metric-only model calculates rectangular base volume as length in metres × width in metres × depth in millimetres ÷ 1,000. Required volume is that net volume multiplied by 1 + allowance percent ÷ 100. The allowance is entered once before any supplier rounding; it is not a prescribed waste or compaction factor.

Calculated tonnes = required cubic metres × entered tonnes per cubic metre. Order tonnes = ceil(calculated tonnes ÷ order increment) × order increment. The increment must be positive. The default density is illustrative and is not a universal property of gravel, sand or aggregate.

Material cost is ordered tonnes × quoted price per tonne, rounded half-up to cents. The entered delivery fee rounds separately and applies once only to a positive order. Zero length, width or depth means zero volume, no purchase and no delivery fee. Unentered transport, handling, tax and installation costs are excluded.

Confirm product, moisture, grading and loose versus compacted material state with the supplier. This tool does not convert between those states or infer an extra compaction allowance. Supplier coverage calculators are approximate purchasing aids. The model does not establish pavement thickness, bearing capacity, drainage, compaction requirements or construction suitability.

Worked example

A 10 m × 5 m area at 100 mm depth is 5 m³. A 10% allowance gives 5.5 m³. At an entered 1.6 tonnes/m³, the calculated mass is 8.8 tonnes. A 0.5-tonne order increment rounds this to 9 tonnes. At an illustrative 45 per tonne, material is 405; adding 80 delivery gives 485 in the selected currency. The density, price and allowance are example inputs.

Sources and assumptions

The source material explains the underlying calculation or pricing structure. Entered prices, costs, schedules and scenario choices are your assumptions; this tool does not obtain supplier quotes or predict actual results.

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