How do you convert material volume to weight?
Every material has a density — a weight per unit of volume — and the whole calculation is volume × density = weight. The catch is that densities differ a lot: dry sand is about 1.6 t/m³, gravel around 1.5–1.7, concrete about 2.4, and topsoil nearer 1.2–1.3. So the same cubic metre can weigh under a tonne or well over two depending on what's in it. The calculator stores realistic densities for each common material so you don't have to look them up.
Why does a cubic metre of one material weigh more than another?
It comes down to how tightly packed the material is. Water is exactly 1 tonne per cubic metre by definition; anything denser than water sinks. Crushed stone and wet sand are heavy because the grains pack closely and hold little air; wood chips, dry topsoil and mulch are light because they're loose and full of gaps. Moisture matters too — wet sand can weigh 20–30% more than dry, which is why deliveries are often heavier than a textbook figure.
Ordering by the tonne vs by the cubic metre (or yard)
Suppliers sell some materials by weight (the tonne) and others by volume (the cubic metre or cubic yard), and quarries often quote in tonnes while you've measured a hole in cubic metres. Being able to flip between the two is what lets you compare prices and order the right amount. As a rule of thumb, 1 cubic yard ≈ 0.76 cubic metres, and for most aggregates a cubic yard lands around 1.3–1.5 tonnes.
Getting the amount right for your project
Measure the space in three dimensions to get the volume — length × width × depth — then convert to weight for ordering. For slabs and paths, keep depth in the same units as the rest. Add a waste/compaction allowance: aggregates settle, so order about 10% extra for a base that will be compacted. The calculator gives you both the volume and the weight so whichever way your supplier sells, you have the number.
Densities are typical reference values and vary with moisture, compaction and source. Confirm with your supplier for critical orders.
Frequently asked questions
How much does a cubic metre of sand weigh?
Dry sand is about 1.6 tonnes per cubic metre; wet sand can be 1.9–2.0. So a cubic metre of sand is roughly 1,600 kg dry.
How much does a cubic yard of gravel weigh?
Around 1.3–1.5 tonnes (about 2,800–3,300 lb), depending on the stone and moisture. A cubic yard is about 0.76 m³.
How do I convert cubic metres to tonnes?
Multiply the volume by the material's density: sand ≈ 1.6, gravel ≈ 1.5–1.7, concrete ≈ 2.4, topsoil ≈ 1.2–1.3 t/m³. The calculator has these built in.
How much does concrete weigh per cubic metre?
Standard concrete is about 2.4 tonnes per cubic metre (roughly 4,000 lb per cubic yard).
Does moisture change the weight?
Yes, a lot — wet sand and gravel can weigh 20–30% more than dry. Use the wet density if the material has been rained on or is delivered damp.