About This Calculator
This calculator estimates the amount of gravel or crushed stone needed for driveways, paths, sub-bases, and landscaping projects. It accounts for compaction when using sub-base materials.
Recommended Depths
| Application | Depth |
|---|---|
| Decorative / garden paths | 30-50 mm |
| Driveway surface | 50-75 mm |
| Sub-base (pedestrian) | 100-150 mm |
| Sub-base (vehicular) | 150-225 mm |
Tips
- • Sub-base materials compact by 20-25%, so order more than the finished volume
- • Use a weed membrane underneath decorative gravel
- • Edging helps contain gravel and maintain neat boundaries
- • Add 5-10% wastage for uneven ground or spillage
Ready to Calculate?
Enter your area and depth to get volume, weight, and delivery requirements.
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UKUK Building Regulations
References & Sources
Standards Cited
- BS EN 13242 — Aggregates for unbound and hydraulically bound materials for use in civil engineering work
Defines aggregate classifications including MOT Type 1 sub-base material - BS 7533-3 — Pavements constructed with clay, natural stone or concrete pavers
Specifies sub-base and bedding layer depths for paved areas
Formulas Used
- Compacted target volume:
compactedVolume = area × depth
Source: Basic geometry - Loose order volume:
looseVolume = compactedVolume × compactionFactor
Source: BS EN 13242 — A factor of 1.25 means 1.25m3 loose compacts to 1.0m3, a 20% reduction from loose volume - Weight from basis-matched volume:
weight = densityBasisVolume × density × (1 + wastage/100)
Source: Material-specific densities — Use compacted target volume for a compacted density and loose volume for a loose density. Compaction changes bulk volume, not mass. - Delivery units:
units = ceil(orderMass / bagMass) or ceil(looseOrderVolume / loadVolume)
Source: Supplier delivery-unit basis
Key Assumptions
- Quoted bulk densities: loose crushed stone ~1750 kg/m3, loose pea gravel ~1600 kg/m3, compacted MOT Type 1 ~2000 kg/m3 — BS EN 13242 / industry standard
- Sub-base loose-volume factor 1.25 (1.25m3 loose produces 1.0m3 compacted, a 20% reduction) — BS EN 13242 / Highways Agency standards