There is no point reaching for a calculator that cannot show its working. This one starts from depth, surface length, waste factor and surface width and reports quantity, weight and c stone, so you can see how each answer follows from the numbers you entered.
What Is the Crushed Stone Calculator?
The crushed stone calculator turns depth, surface length, waste factor and surface width into quantity, weight and c stone, so you can order the right amount of material the first time.
Material estimates are where projects go over budget. Getting the quantities right before the delivery arrives is worth more than any discount on the order.
How to Measure for the Crushed Stone
Measure everything in the same unit and take the largest dimension you can reasonably use rather than the average. Formwork, ground conditions and cutting waste all push the real figure above the theoretical one.
Where a plan calls for a specific thickness, check it against local building regulations before you order. The calculator reflects the relationship, not the code.
Allowing for Waste and Errors
Order a little more than the calculation suggests. The gap between the theoretical quantity and what actually arrives on site is normally waste, spillage, over-excavation and uneven grading, and all of it comes out of the same budget.
Write the figures down and compare them with what you actually used on site. That is how you build an estimate you can trust for the next job.
A Worked Example
Working through an example, with depth set to 10, surface length set to 5, waste factor set to 2, the calculator returns stone of 185.19, and extra of 3.7, and quantity of 188.89. Substitute your own figures and the same steps produce the same kind of answer.
Frequently Asked Questions
What do I need to work out quantity?
Enter depth, surface length, waste factor and surface width. The calculator then works through the relationship and reports quantity, weight and c stone.
What does the crushed stone actually calculate?
It takes depth, surface length, waste factor and surface width and converts them into quantity, weight and c stone using the standard relationship for this problem. Each step is applied in turn, so every output is traceable back to the numbers you typed in.
How should I enter depth?
Use the value you actually have, in the unit shown next to the field. Enter every value in the same unit system. The calculator assumes the figures you supply are consistent, so it cannot correct a mistake that happens before the calculation starts.
Is the answer exact?
It is as exact as the formula and the inputs allow. The method itself is the standard one for this problem, so the only sources of error are the figures you enter and the precision you ask for.
Can I use this for a quick estimate as well as a precise answer?
Yes. The calculator is built for quick checks, so round your inputs to a sensible number of significant figures and the result will be just as useful. If you need more precision, keep the same method and add digits to the inputs rather than adjusting the method itself.