About

What this site does

36 calculators for construction and landscaping materials. Each one takes an area and a depth and returns a volume, a weight, what to order and a cost from a price you enter yourself.

Where the numbers come from

122 published bulk density figures from named suppliers, quarry operators, builders merchants and state highway departments. Every one is listed on the sources page with the supplier, the figure exactly as that supplier prints it, and the date the page was read.

Each material needs at least three independent suppliers. Where only one or two publish a figure, the range is marked provisional on the page rather than presented as settled.

What the calculator does not do

It returns material quantity and material cost. It does not estimate delivery, labour or equipment hire, because those depend on your supplier and your site, and a percentage presented as a delivery charge would be a guess wearing a number.

How the maths is checked

The arithmetic is a separate TypeScript module with its own tests, covering unit conversion in both directions, circle and L-shape areas, the endpoints of every density range, rounding up for anything sold in whole bags, and rejecting zero or negative input. Worked examples are checked against figures suppliers publish rather than against the calculator's own output: a cubic yard of concrete against Cemex's two tons, an 850kg bulk bag of MOT Type 1 against Mainland Aggregates' five square metres at 100mm.

Units

US visitors get cubic yards, tons, cubic feet and inches. Everywhere else gets cubic metres, tonnes and millimetres. The toggle is always visible and nothing is converted without it being shown.