Building Material Density Table – kg/m³, t/m³ & lb/ft³
Typical planning density ranges for soil, sand, gravel, crushed stone, concrete, masonry, steel and timber. Use the table to convert volume into estimated mass, but match the density to the material state and use supplier, test or project data when accuracy matters.
Typical construction material density ranges
Use these values for preliminary quantity checks when a project-specific value is not yet available. For bulk materials, the condition named in the first column matters just as much as the number itself.
| Material | Typical density kg/m³ | t/m³ | Approx. lb/ft³ | Planning note |
|---|---|---|---|---|
| Topsoil, loose | 900–1,300 | 0.90–1.30 | 56–81 | Moisture and organic content vary strongly. |
| Soil / earth, loose | 1,200–1,600 | 1.20–1.60 | 75–100 | Use excavated-material or site data if available. |
| Sand, dry | 1,500–1,650 | 1.50–1.65 | 94–103 | Loose bulk value; grading and packing still matter. |
| Sand, wet | 1,800–2,000 | 1.80–2.00 | 112–125 | Water content increases bulk mass. |
| Gravel, dry | 1,600–1,800 | 1.60–1.80 | 100–112 | Varies with grading, particle shape and void ratio. |
| Crushed stone, loose | 1,500–1,800 | 1.50–1.80 | 94–112 | Bulk density, not the density of solid rock. |
| Fresh / normal concrete | 2,300–2,450 | 2.30–2.45 | 144–153 | Mix design changes the actual density. |
| Brick masonry | 1,600–2,000 | 1.60–2.00 | 100–125 | Depends on unit type, voids and mortar. |
| Structural / reinforcing steel | ≈7,850 | ≈7.85 | ≈490 | Useful for theoretical steel mass from volume or section data. |
| Softwood timber | 400–600 | 0.40–0.60 | 25–37 | Species and moisture can cause large variation. |
How to use a range: if the exact density is unknown, calculate both ends of the range. That gives a planning mass interval instead of pretending one midpoint is exact.
Convert volume into mass
Example: 3 m³ of aggregate at an assumed 1.70 t/m³ gives about 5.10 t. If the supplier gives 1.58 t/m³ for the exact product, the same 3 m³ becomes 4.74 t. The volume has not changed; only the density assumption has.
In US units the same principle applies: multiply volume in ft³ by density in lb/ft³ to estimate pounds. If your calculator works in cubic yards, convert consistently before multiplying.
Density-state decision grid: which density belongs to your volume?
The most common density mistake is not arithmetic. It is combining a volume measured in one physical state with a density that describes another.
| Your quantity | What the volume describes | Density to look for | Typical use |
|---|---|---|---|
| Excavation before digging | Soil in place / bank volume | In-situ or bank density | Mass of material removed from the excavation. |
| Loose spoil after excavation | Expanded loose material | Loose excavated bulk density | Truck body volume and handling checks. |
| Delivered gravel or crushed stone | Loose supplier material | Supplier loose bulk density | Convert ordered m³ or yd³ to tonnes / short tons. |
| Installed aggregate layer | Compacted finished layer | Compacted bulk density or project-specific value | Installed mass and compaction planning. |
| Concrete in a slab or footing | Fresh/normal concrete volume | Concrete density for the specified mix | Approximate mass and handling checks. |
| Steel bar or section | Solid material / known geometry | Material density or published mass per metre/foot | Theoretical steel mass. |
Loose, in-situ and compacted are not interchangeable
Excavated soil commonly occupies more volume after digging because the original structure is disturbed. Aggregate delivered by a quarry is also a bulk material containing voids. Once placed and compacted, the same material may occupy less volume.
If you calculate 10 m³ of compacted sub-base and then multiply it by a loose-delivery density without checking the supplier's basis, the mass estimate may be inconsistent even though the multiplication is mathematically correct.
Always pair volume state + density state. For excavation work, keep bank volume, swell/bulking and loose spoil volume as separate quantities.
Bulk density versus solid-material density
Loose gravel and crushed stone contain air voids between particles. Their bulk density therefore differs from the density of the solid mineral itself. A truck, stockpile or aggregate layer is usually a bulk-volume problem, so a solid-rock density is normally the wrong input.
Steel is different. A reinforcing bar is treated as solid steel, so its material density is much more stable. For standard reinforcing bars, a published mass per metre or per foot is usually even better than recreating the mass from nominal diameter.
Ask what the quoted number represents before copying it into a calculator.
Where to get a better density value
Supplier or quarry data
For gravel, crushed stone, sand and other bulk products, supplier documentation or a quotation for the exact product is usually more useful than a generic table.
Project specification or test
Earthworks and compacted layers may have project-specific density, moisture or compaction requirements. Use those values when the estimate supports construction planning.
Manufacturer documentation
For manufactured products and mixes, use the declared product or mix information. Do not substitute a visually similar material automatically.
Practical rule: use this table for early planning, then replace the planning value with the exact project value before a critical order, truck-load limit or structural decision.
Worked examples with a density range
Example 1: crushed stone
A project needs 4.0 m³ of loose crushed stone. The table gives a planning range of 1.50–1.80 t/m³.
Until the supplier confirms the actual bulk density, it is more transparent to plan for roughly 6.0–7.2 t than to present one unsupported exact mass.
Example 2: normal concrete
A 2.5 m³ pour with a planning density range of 2.30–2.45 t/m³ corresponds to about 5.75–6.13 t of fresh concrete. This can be useful as a reasonableness check, but concrete delivery is normally ordered by volume and the actual mix data takes priority.
Does your mass result look realistic?
- If a small aggregate layer produces tens or hundreds of tonnes, recheck whether depth was entered in metres instead of centimetres or feet instead of inches.
- If wet sand weighs less than the same volume of dry sand using your chosen inputs, recheck the density values.
- If an excavation truck-load estimate looks too low, confirm whether you used bank volume or loose spoil volume after bulking.
- If steel appears only slightly heavier than timber for the same solid volume, the unit conversion is probably wrong.
- If the result controls a vehicle payload or lifting decision, do not rely on a generic midpoint from this table.
A density table is best used as a sanity-check and planning reference, not as a substitute for project-specific data.
Common density-table mistakes
| Mistake | Why it matters | Better approach |
|---|---|---|
| Using solid-rock density for loose crushed stone | Ignores voids between particles and can greatly overstate bulk mass. | Use loose bulk density for a loose stockpile or delivery volume. |
| Ignoring moisture | Water can materially change soil, sand and timber mass. | Use a value matching expected moisture condition. |
| Mixing kg/m³ and t/m³ | Creates a factor-of-1,000 error. | Remember that 1,700 kg/m³ = 1.70 t/m³. |
| Mixing m³ and ft³ | Produces meaningless mass even if the density number is valid. | Convert the volume or density first so the units match. |
| Using one midpoint as an exact value | Hides uncertainty in variable bulk materials. | Show a low/high mass range until better data is available. |
For construction students and apprentices
Density connects geometry to mass. A volume tells you how much space a material occupies; density tells you how much mass is associated with each unit of that volume. The important skill is not only multiplying numbers but also checking that the units and material state match.
Practice: estimate the mass range of 2.8 m³ of dry gravel using 1.60–1.80 t/m³. The low estimate is 4.48 t and the high estimate is 5.04 t. Then explain why a supplier-specific density would narrow that range.
Check question: why should you not automatically use the density of solid stone for a 5 m³ loose gravel delivery? Because the 5 m³ includes voids between particles, so it needs a bulk-density value describing the loose material.
Continue from volume to weight and ordering
Choose the next tool according to the quantity you are planning.