How area and depth become a material quantity
Enter a measured area directly or let the calculator multiply a rectangular length by width. Area multiplied by depth gives the geometric volume. The selected allowance is then added before volume is multiplied by the entered bulk density. Inputs, results, print output and CSV stay in the measurement system you select.
order volume = net volume × (1 + allowance ÷ 100)
mass = order volume × bulk density
Metric mode uses square metres and millimetres for the measured work, kilograms per cubic metre for density, and reports cubic metres, kilograms, metric tonnes and payloads in tonnes.
US customary mode uses square feet and inches for the measured work, pounds per cubic foot for density, and reports cubic feet, cubic yards, pounds, short tons and payloads in short tons.
Indicative density starting points
These values are deliberately editable. They are not material certificates and should not override a project specification or supplier declaration.
| Material | Preset kg/m³ | Basis |
|---|---|---|
| Type 1 sub-base | 2,200 | Compacted |
| 6F2 recycled aggregate | 2,000 | Compacted |
| Asphalt / tarmac | 2,350 | Laid |
| Normal concrete | 2,400 | Hardened |
| Gravel / shingle | 1,650 | Loose |
| Dry construction sand | 1,600 | Loose |
| Screened topsoil | 1,300 | Loose |
| Material | Preset lb/ft³ | Basis |
|---|---|---|
| Type 1 sub-base | 137.3 | Compacted |
| 6F2 recycled aggregate | 124.9 | Compacted |
| Asphalt / tarmac | 146.7 | Laid |
| Normal concrete | 149.8 | Hardened |
| Gravel / shingle | 103.0 | Loose |
| Dry construction sand | 99.9 | Loose |
| Screened topsoil | 81.2 | Loose |
Worked gravel, asphalt, sand and topsoil examples
Gravel: 1,000 ft² at 4 inches deep
With no allowance, the geometric quantity is 333.333 ft³, or 12.346 yd³. At the editable 103.0 lb/ft³ gravel preset, that is about 34,333 lb or 17.17 US short tons before any allowance.
Asphalt: 100 m² at 50 mm compacted depth
The net volume is 5.000 m³. Using the editable 2,350 kg/m³ laid-asphalt preset gives 11.750 t; a 5% ordering allowance increases the estimate to 12.338 t.
Sand: 60 m² at 50 mm depth
The net volume is 3.000 m³. At the editable 1,600 kg/m³ dry-sand preset, the estimated mass is 4.800 t before allowance.
Topsoil: 500 ft² at 4 inches deep
The net volume is 166.667 ft³, or 6.173 yd³. At the rounded 81.2 lb/ft³ topsoil preset, that is approximately 13,533 lb or 6.77 US short tons before allowance.
Choosing an allowance
An allowance may cover level variation, compaction, trimming, contamination and ordering increments. It is not a substitute for converting a loose supplier volume to a specified compacted volume. Keep that distinction explicit.
Frequently asked questions
How much gravel do I need?
Multiply the covered area by the placed depth to obtain volume, add an ordering allowance, then use a supplier bulk density if weight or tons are required.
How do I calculate asphalt or tarmac tonnage?
Multiply paved area by compacted layer depth, then multiply that volume by the verified laid asphalt density. Add only the allowance appropriate to the job and supplier ordering increments.
Can I calculate sand or topsoil quantities?
Yes. Select sand or topsoil, enter the area and finished depth, and replace the indicative density with a supplier value when weight is needed.
Are the material densities exact?
No. Actual bulk density changes with grading, source, moisture, voids and compaction. Replace the presets with supplier or test data wherever available.
Does the calculator mix measurement systems?
No. Choose Metric or US customary and the inputs, result card, printed report and CSV export stay in that system. Use the dedicated unit converter when you intentionally need a cross-system conversion.