How deep should gravel be for a driveway?

For a driveway, gravel should be laid at least 100mm (4 inches) deep on top of a compacted Type 1 sub-base. Use our Type 1 Sub-Base Calculator (/landscaping/type-1-sub-base-calculator) to work out sub-base quantities. Decorative driveways may use 50mm of decorative gravel over 100-150mm of sub-base. Without adequate depth, gravel will shift under vehicle weight and develop ruts.

How much does gravel weigh per m³?

Gravel weight varies by type: decorative gravel is typically 1.5 tonnes per m³, pea gravel around 1.6 tonnes per m³, and driveway-grade angular gravel (20mm) around 1.8 tonnes per m³. Slate chippings are lighter at roughly 1.5 tonnes per m³. This gravel tonnage calculator uses the correct density for your chosen gravel type.

What is the best gravel for a UK driveway?

Angular 20mm gravel (also called driveway aggregate or driveway shingle) is the most popular choice for UK driveways as it locks together under compaction. Golden gravel, cotswold stone, and granite chippings are all popular. Always lay gravel over a proper Type 1 MOT sub-base with a geotextile membrane to prevent mixing with the subsoil.

How deep should decorative gravel be?

Decorative gravel for garden paths and borders should be 30-50mm deep. At 50mm depth, you get good coverage that stays in place and suppresses weeds. Always use a weed membrane underneath. For a solid paved surface instead, see our Paving Slab Calculator (/landscaping/paving-slab-calculator).

How many bulk bags of gravel do I need?

A standard bulk bag contains 0.75 m³ of gravel (roughly 850kg-1 tonne depending on gravel type). For a typical single-car driveway (3m x 6m at 100mm deep), you would need approximately 1.8 m³ — so 3 bulk bags. This gravel quantity calculator works this out automatically. For French drain gravel, see our French Drain Calculator (/landscaping/french-drain-calculator).

TradeCalcs

Gravel Calculator — How Much Gravel Do I Need?

Calculate gravel or aggregate quantities in tonnes and bulk bags for driveways, paths and decorative areas.

Area Length

Length of the area to cover

Area Width

Width of the area to cover

Gravel Type

Density: 1.5 t/m³

Depth

50mm decorative, 100mm driveways

Include wastage allowance

Adds 10% extra for uneven ground and compaction

Wastage Percentage

10% recommended for most projects

Price Per Tonne (optional)

Enter your supplier price for a cost estimate

How We Calculate This

Our gravel calculator multiplies your area by the required depth to get the volume in cubic metres, then converts to weight using the appropriate density for your chosen gravel type.

The formula

Volume (m³) = Length (m) × Width (m) × Depth (m)

Weight (tonnes) = Volume (m³) × Density (t/m³)

Gravel densities we use

Decorative gravel (10-20mm): 1.5 tonnes per m³
Driveway gravel (20mm angular): 1.8 tonnes per m³
Pea gravel (10mm): 1.6 tonnes per m³
Slate chippings (20-40mm): 1.5 tonnes per m³

Recommended depths

Decorative areas and borders: 50mm
Pathways: 50-75mm
Driveways: 100mm (over compacted sub-base)

Always add 10% wastage to account for uneven ground and compaction. For driveways, ensure you lay a proper Type 1 MOT sub-base (100-150mm compacted) before adding the decorative gravel layer.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Verify with your supplier.