Overview
Density values are planning midpoints compiled from multiple UK product specifications. Supplier-specific figures always take precedence over anything published here.
Assumptions and accuracy
Each material record stores a planning midpoint plus a typical range, a plain-English note, a source label and a review date.
Calculators apply: weight = area × depth × planning density, then your chosen ordering (and optional compaction) allowance. Bag counts divide the total kilograms by the printed net bag weight and round up.
Rounding happens only at display; internal arithmetic keeps full precision.
Planning density values
Use supplier product data whenever available. These figures are planning defaults shared by every calculator on the site.
| Material | Category | Planning density | Typical range | Compaction |
|---|---|---|---|---|
| MOT Type 1 | Sub Base | 2.20 t/m³ | 2.00–2.30 t/m³ | Relevant |
| MOT Type 3 | Sub Base | 2.10 t/m³ | 1.90–2.20 t/m³ | Relevant |
| Recycled Type 1 | Recycled | 2.00 t/m³ | 1.80–2.20 t/m³ | Relevant |
| 6F2 / 6F5 crushed aggregate | Recycled | 2.00 t/m³ | 1.80–2.20 t/m³ | Relevant |
| Road planings | Recycled | 2.00 t/m³ | 1.80–2.20 t/m³ | Relevant |
| Sharp sand | Sand | 1.60 t/m³ | 1.50–1.70 t/m³ | Usually no |
| Building sand | Sand | 1.50 t/m³ | 1.40–1.60 t/m³ | Usually no |
| Kiln-dried sand | Sand | 1.50 t/m³ | 1.40–1.60 t/m³ | Usually no |
| 10mm pea shingle | Gravel | 1.60 t/m³ | 1.40–1.70 t/m³ | Usually no |
| 20mm gravel / shingle | Gravel | 1.60 t/m³ | 1.40–1.70 t/m³ | Usually no |
| Decorative gravel | Decorative | 1.50 t/m³ | 1.30–1.70 t/m³ | Usually no |
| Slate chippings | Decorative | 1.60 t/m³ | 1.40–1.80 t/m³ | Usually no |
| Gabion stone | Gravel | 1.50 t/m³ | 1.40–1.60 t/m³ | Usually no |
| Self-binding gravel | Gravel | 1.90 t/m³ | 1.80–2.10 t/m³ | Relevant |
| Crushed concrete | Recycled | 1.90 t/m³ | 1.70–2.10 t/m³ | Relevant |
| Limestone scalpings | Sub Base | 2.00 t/m³ | 1.80–2.20 t/m³ | Relevant |
| Ballast | Sand | 1.70 t/m³ | 1.60–1.80 t/m³ | Usually no |
| Generic aggregate | General | 1.70 t/m³ | 1.50–2.20 t/m³ | Usually no |
How to use this calculator
- Find the material in the density table for its midpoint and range.
- Compare against your supplier's product page or data sheet.
- Enter the supplier figure in the calculator's density override for a tighter estimate.
Frequently asked questions
Why do suppliers quote different MOT Type 1 densities?
Because the material genuinely varies. Published UK examples span roughly 2.0 t/m³ (Mainland Aggregates) to about 2.3 t/m³ for limestone Type 1 (Smiths Bletchington), which is why we publish a range with a 2.2 t/m³ planning midpoint rather than one exact number.
Are these densities mandated by UK law?
No. Generic density values are not mandated by law. Project specifications reference material standards — for sub-base contexts, the current Specification for Highway Works published by Standards for Highways (restructured September 2025; formerly the MCHW Series 800 structure).
References and source notes
- Mainland Aggregates — MOT Type 1 sub-base product data (≈2.0 t/m³)
- Smiths Bletchington — MOT Type 1 product data (limestone, ≈2.3 t/m³)
- Northern Building Materials — 20mm gravel 850kg bulk bag product data
- Standards for Highways — current Specification for Highway Works (MCHW, restructured September 2025)