Updated
March 27, 2026
Reviewed against the current calculator logic, structured content, and internal linking used on BuildCostLab.
Aggregate and Base Estimating
Turn the job dimensions into a sensible ballast 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.
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.
Trust
How we publish
See the calculator methodology and editorial policy for the standards behind these pages.
Use the calculator first
The quickest path is to start with Ballast 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 ballast 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 Ballast Calculator.