Bulk density of construction materials: reference table and volume ↔ weight calculator
How many tonnes of sand will you need for 12 m³ of screed? How many truckloads is one foundation? These questions come up on site every day — and they almost always boil down to a single number: the material's bulk density.
In this article you will find out what bulk density actually means, why it matters for quantity take-offs and deliveries, get a ready-to-use reference table for the most commonly used materials, and an interactive calculator that converts volume to weight (and back) in seconds.
What is bulk density
Bulk density is the mass per unit volume of a material, expressed in kilograms per cubic metre (kg/m³). Unlike pure particle density, bulk density also accounts for the voids between grains or particles — that is why a loose material such as sand weighs less than the density of the mineral itself.
Why this matters in practice:
- Deliveries and transport — trucks and fees are calculated in tonnes, but materials are ordered in cubic metres.
- Quantity take-offs (BoQ) — converting between volume and weight has to be correct, otherwise quantities and costs will not match.
- Loads and structures — the self-weight of materials goes directly into structural calculations.
- Storage — load-bearing capacity of slabs, racks and platforms.
Reference table: bulk density of construction materials
Averaged reference values for the most commonly used materials:
| Material | Bulk density (kg/m³) | Tonnes per 1 m³ |
|---|---|---|
| Reinforced concrete | 2500 | 2.50 |
| Concrete (normal) | 2400 | 2.40 |
| Asphalt concrete | 2350 | 2.35 |
| Cement mortar | 2100 | 2.10 |
| Clay (earth) | 1900 | 1.90 |
| Ballast (sand-gravel mix) | 1850 | 1.85 |
| Lightweight concrete | 1800 | 1.80 |
| Sand (wet) | 1800 | 1.80 |
| Solid bricks | 1800 | 1.80 |
| Gravel | 1700 | 1.70 |
| Lime mortar | 1700 | 1.70 |
| Sand (dry) | 1600 | 1.60 |
| Cement (loose) | 1500 | 1.50 |
| Crushed stone | 1500 | 1.50 |
| Topsoil | 1500 | 1.50 |
| Hollow bricks | 1300 | 1.30 |
| Gypsum | 1200 | 1.20 |
| Water | 1000 | 1.00 |
| Timber (hardwood) | 750 | 0.75 |
| AAC blocks (Ytong) | 600 | 0.60 |
| Timber (softwood) | 550 | 0.55 |
| Expanded clay (LECA) | 400 | 0.40 |
| Mineral wool | 100 | 0.10 |
| XPS | 35 | 0.035 |
| EPS (styrofoam) | 20 | 0.020 |
The values are averaged and intended as guidance. Moisture, fraction and degree of compaction can change the weight significantly — for precise calculations use your supplier's data.
Calculator: volume ↔ weight
Pick a material and type in either of the two fields — the other one is calculated automatically. It works in both directions (volume → weight and weight → volume), and the button in the middle swaps the units. Metric and imperial units are supported: m³, litres, cm³, ft³, yd³ for volume and kg, tonnes, grams, lb (pounds) for weight.
Bulk density: 2,400 kg/m³
Type in either field — the other is calculated automatically. Volume (m³, litres, cm³, ft³, yd³) and weight (kg, tonnes, g, lb) units are supported. Bulk density values are averaged reference data.
How to calculate by hand
The formula is simple:
Weight (kg) = Volume (m³) × Bulk density (kg/m³)
And for the opposite direction:
Volume (m³) = Weight (kg) ÷ Bulk density (kg/m³)
Example 1 — cubic metres to tonnes: You need 8 m³ of gravel. 8 × 1700 = 13 600 kg = 13.6 tonnes.
Example 2 — tonnes to cubic metres: One truck (25 tonnes) of sand has been delivered. 25 000 ÷ 1600 = 15.6 m³.
Mistakes that cost money
- Ignoring moisture — wet sand can weigh 15–20% more than dry sand. When ordering by tonnage this is a real difference in quantity.
- Confusing loose with compacted — after compaction the volume shrinks and the bulk density rises. Order by delivered (loose) volume, design by compacted volume.
- Rounding to a "nice number" — at large quantities, small differences in kg/m³ add up to whole tonnes and truckloads.
In Construction Team, conversions between units of measure and values in quantity take-offs are applied consistently, so volume, weight and cost always reconcile — without manual calculator maths and without delivery mismatches.
Frequently asked questions
What is the difference between bulk density and particle density?
Particle density describes the mass of the material itself, without the voids between particles (e.g. a single grain of gravel). Bulk density also accounts for the air between the particles — that is why loose sand has a lower bulk density than the density of quartz. For deliveries and quantity take-offs you almost always work with bulk density.
Why do real-world values differ from the table?
Bulk density depends on moisture content, fraction (grain size), degree of compaction and the producer. Wet sand weighs considerably more than dry sand. The table gives averaged reference values — for precise calculations use the supplier's data or laboratory testing.
How do I convert cubic metres to tonnes?
Multiply the volume in cubic metres by the bulk density in kg/m³ and divide by 1000. Example: 10 m³ of sand × 1600 kg/m³ = 16,000 kg = 16 tonnes. The calculator in this article does it automatically — you pick a material, enter the quantity and see the result instantly.