Calculate Materials

How much material do you need?

Measure the area, pick a depth, and get the volume, the weight and what to order, in cubic yards and tons or cubic metres and bulk bags.

Every density comes from a named supplier. 122 published figures across 32 materials, each with its source and the date it was read. See them all.

Concrete calculator

Shape of the area
ft
ft
in
Typical:
%
Use your supplier's density
kg/m3

Enter your measurements to see what to order.

Calculators by material

Counted, not weighed

Pavers, brick, turf and slabs are ordered by the piece. These calculators return a count and the base material that goes underneath.

How deep to lay it

How the calculators work

Area times depth gives a volume. Volume times the material's bulk density gives a weight. Weight divided by your supplier's bag or load size gives what to order, rounded up for anything sold in whole bags and left alone for anything sold loose.

Why the weight of a load varies so much

Bulk density changes with grading, moisture and how the material was loaded. Published figures for gravel run from 1424 to 1780 kg per cubic metre, which is a 25 percent spread on the same order. Each calculator shows that range and lets you replace it with the figure your own supplier states.

Ordering in the UK and Australia

UK merchants sell by the tonne and the bulk bag, nominally 850kg but genuinely 700 to 1000kg depending on the supplier and how damp the load is. Australian yards sell by the cubic metre and the scoop, half a cubic metre for soil and mulch and 0.4 of a cubic metre for stone. The aggregate calculator and the MOT Type 1 calculator work in those units and at those depths.

Every calculator

Common questions

36 material calculators, 7 counted by the piece, 6 depth guides, 5 answer pages.