Craft Quantities
Plan & Takeoffs

Materials and physical properties

Bulk densities of construction materials

What a cubic metre of loose material actually weighs, in both systems, as this site's calculators compute it. These are bulk densities — the weight of the material as it sits in a heap or a lorry, air gaps included — and not the density of the substance itself. A cubic metre of gravel is nowhere near the weight of a cubic metre of the rock it was crushed from, because roughly a third of it is the space between the stones.
  • 10Rows, each with its source
  • 53Calculators compute with it
  • CC BY 4.0Free to reuse, with credit

What moves the figure

No standard fixes any of these. What a yard delivers depends on where the material came from, how it is graded, how long it has been stockpiled and what the weather has been doing to it, so every row is a working figure rather than a published value. The single most useful thing on this page is not a number: it is that moisture and compaction move bulk density further than the difference between two similar materials does. Wet sand is a fifth heavier than the same sand dry, and that fifth is the difference between a legal load and an overweight one on a small tipper.

A planning figure, not a fact

Use them to size a skip, order a delivery or sanity-check a weight, and weigh a sample whenever a load sits close to a limit. A density read off any table — this one included — is a planning figure, and a weighbridge ticket is a fact.

Where the calculators disagree

Five rows are published as ranges rather than figures: gravel, topsoil, asphalt, bark mulch and compost. For each of them this site's own pages compute with more than one working figure — the cubic-yards-to-tons converters, the material weight calculator and the generic volume-to-weight pages were written against different planning values — and publishing any one of those figures alone would claim an agreement the site does not have. Each of those rows names the pages behind its range. The other five rows are single figures because the calculators that use them agree to within the rounding between kilograms and pounds.

The table

Every row, and where it comes from

Every row is trade practice — widely quoted, and not cited.

JSON
10 rows
Bulk densities of construction materials. 10 rows, each stating where its figures come from.
SourceCopy
Gravel, dry loose1600–1661100–103.7Trade practice8 calculators
Loose in a pile. Compacted in a trench it is heavier, and washed gravel drains so it does not hold the water that pushes wet sand up by a fifth. The Gravel Cubic Yards to Tons pages work on 1.4 short tons per cubic yard, which is 1,661 kg/m³, where the material weight and generic volume-to-weight pages use 1,600. The gravel pages' own limitations put stone sold as gravel anywhere from 1.2 to 1.6 tons per cubic yard.
Sand, dry loose1600100Trade practice7 calculators
Dry. Sand delivered from a yard is rarely dry, and the wet figure below is the one a delivery ticket usually reflects.
Sand, wet1920120Trade practice1 calculator
Twenty per cent heavier than the same sand dry, which is the difference between a legal load and an overweight one on a small tipper.
Topsoil, loose1300–142481–88.9Trade practice8 calculators
Screened and loose. Topsoil with clay in it, or stockpiled and rained on, is materially heavier than this. The Topsoil Cubic Yards to Tons pages work on 1.2 short tons per cubic yard, which is 1,424 kg/m³, where the material weight page uses 1,300 and the generic volume-to-weight pages 2,200 lb per cubic yard.
Concrete, normal weight2400150Trade practice14 calculators
Normal-weight concrete, cured, without reinforcement. Lightweight mixes run a third lower and are a different design decision entirely.
Crushed stone155097Trade practice5 calculators
Loose. Angular crushed stone locks together when compacted and gains more from compaction than a rounded gravel does.
Asphalt, compacted2323–2350145–147Trade practice5 calculators
Compacted, in place. Loose mix in the back of a lorry is lighter, so a tonnage figured from compacted density buys the right amount of material and the wrong amount of space. The Asphalt Cubic Yards to Tons pages and the Asphalt Driveway Calculator work on 145 lb/ft³ for compacted hot mix, which is 2,323 kg/m³, where the material weight page uses 2,350.
Bark mulch356–47522.2–29.6Trade practice7 calculators
The most variable row on the page, and the one where this site's own pages differ most. Species, particle size and how long a load has been rained on all move the density of a bark or wood mulch, and a wet load is heavier again. The generic volume-to-weight pages use 600 lb per cubic yard (356 kg/m³), the Bark Mulch Cubic Yards to Tons pages 0.35 short tons per cubic yard (415) and the Mulch Cubic Yards to Tons pages 0.4 (475), where the material weight page uses 400.
Compost550–71234–44.4Trade practice4 calculators
Screened compost, damp as delivered. Drier material is lighter and a load left uncovered through a wet week is heavier. The Compost Cubic Yards to Tons pages work on 0.6 short tons per cubic yard, which is 712 kg/m³, where the material weight page uses 550.
Water100062.4Trade practice15 calculators
At 4 °C, where the definition of the kilogram put it. The only row here that is a definition rather than a bulk material, and it is on the page because the calculators use it as the comparison everything else is read against.

Behind the table

53 calculators compute with this data

Generated from the calculators themselves rather than written, grouped by trade. Open any of them to see a figure from this table at work.

Materials & Quantities

39
The other 33

Landscaping & Outdoor

6

Measurements & Conversions

3

Auto/Utility

3

Plumbing & HVAC

2
Cite this page

Reference data

The rest of the library

Each table here is a view onto data the calculators already compute with, and each names where its figures come from.

Every reference tableStandards cited

  • A source on every row

    A standard, a manufacturer, trade practice or arithmetic — named where the figure is.

  • A range where reality is one

    A band prints whole, never flattened to a single figure.

  • Free to reuse

    CC BY 4.0, and the same rows as JSON. Credit Craft Quantities.

Frequently asked questions

Why does a load of gravel weigh less than the rock it came from?
Because these are bulk densities: the material as it sits in a heap or a lorry, air gaps included. Roughly a third of a load of gravel is the space between the stones, so the same volume weighs well under the solid rock it was crushed from.
How much does moisture change the weight?
More than the difference between two similar materials does. Wet sand is about a fifth heavier than the same sand dry — on a small tipper, the difference between a legal load and an overweight one. Weigh a sample whenever a load sits close to a limit: a density from any table is a planning figure, and a weighbridge ticket is a fact.
Can I use these densities for a structural dead load?
No. They are loose bulk densities for handling and haulage. Normal-weight concrete appears because the site's own weight calculator offers it; a structural dead load is a different figure, arrived at a different way.
Why are some rows a range instead of one figure?
Because this site's own pages compute with more than one working figure for those materials, and publishing any one of them alone would claim an agreement the site does not have. Each of those rows names the pages behind its range.