Aggregate and Base Estimating

Turn the job dimensions into a sensible mot type 1 order

A rough length, width, and depth can usually be turned into a much safer material order once waste and buying format are taken into account.

Updated

March 27, 2026

Reviewed against the current calculator logic, structured content, and internal linking used on BuildCostLab.

Methodology

Planning-first estimate

Use this guide to build a rough material estimate, then confirm it against product coverage data, site conditions, and supplier pack sizes before you order.

Use the calculator first

The quickest path is to start with MOT Type 1 Calculator, then use this guide to sense-check the result and decide what to buy next.

Why this page exists

Best for aggregates, soils, screeds, and fill materials where the order usually starts with volume, then converts into tonnes, bags, or bulk units. This one is tuned for mot type 1 jobs.

Core assumption

Volume calculators assume the job can be reduced to length, width, depth, and a practical density or buying-unit conversion.

Common mistake

Depth mistakes are the biggest problem, followed by using the wrong density and forgetting that loose and compacted materials do not behave identically.

Next step links

Open the full Aggregate and Base Estimating cluster or go straight to the MOT Type 1 Calculator.