How do I work out how many tonnes of aggregate I need?

Multiply the area in square metres by the depth in metres to get cubic metres, then multiply by the material's bulk density in tonnes per cubic metre. Most compacted sub-base materials sit around 1.9–2.0 t/m³, sands around 1.5–1.6 t/m³ and screened topsoil around 1.4 t/m³.

What depth of MOT Type 1 do I need?

As a general guide, 100mm compacted for footpaths and patios, 150mm for domestic driveways, and 200mm or more for vehicle-trafficked yards and access roads. Always follow the engineer's detail where one exists — subgrade condition changes the answer.

Should I add an allowance for compaction?

Yes. Loose material reduces in volume once compacted, so add roughly 10–15% on granular sub-base and capping layers. The calculator below lets you add a waste and compaction allowance.

How many tonnes are in a tipper load?

Around 12–13 tonnes in a 6-wheeler, 19–20 tonnes in an 8-wheel rigid tipper and 28–29 tonnes in an artic bulk tipper. Buying in full loads is usually the most efficient way to take bulk material.

Is the calculator accurate enough to order from?

It gives a sound working estimate for planning. Densities vary with moisture and source, and site conditions vary, so send us the figures with your enquiry and we will sanity-check them against the drawing before anything is loaded.

Tools

Aggregate calculator — area and depth to tonnes.

Enter the area you're covering and the compacted depth, pick a material, and get an estimated tonnage plus how many tipper loads that works out to. Useful for muck-away tonnage too — pick "excavated soil".

Your figures

Length (m)Width (m)Depth (mm)Waste / compaction allowance (%)MaterialCompacted sub-base under drives, roads and hardstandings · assumed bulk density 2 t/m³

Estimated requirement

Tonnes required

13.20

includes 10% waste / compaction allowance

Area: 40.00 m²
Volume: 6.00 m³
Approx. bulk bags (850kg): 16

In vehicle loads

6-wheel grab / rigid tipper2 loads
8-wheel tipper (bulk load)1 load
Artic bulk tipper1 load

Send these figures for a quote

Estimates only — densities vary with moisture and source. We'll check the figures against your drawing before anything is loaded.

Typical bulk densities

Material	Assumed density (t/m³)	Typical use
MOT Type 1 sub-base	2	Compacted sub-base under drives, roads and hardstandings
MOT Type 3 (open graded)	1.9	Permeable sub-base where drainage is required
6F5 / 6F2 capping	1.9	Capping layer over weak formation
Recycled Type 1 (crushed concrete)	1.8	Recycled sub-base and fill
Ballast (all-in)	2	Concreting ballast, 20mm to dust
Sharp / concreting sand	1.6	Screeds, concrete and block paving laying course
Building / soft sand	1.5	Bricklaying and rendering mortar
Pipe bedding stone (4/10, 10mm, 4/20, 20mm)	1.55	Pipe bedding and surround
Pea shingle 6mm	1.5	Drainage, bedding and decorative surfacing
Decorative gravel 20mm	1.6	Driveways and garden surfacing
BS3882 screened topsoil	1.4	Soft landscaping and planting depths
Excavated soil / clay (as dug)	1.7	Use for muck-away tonnage coming off site

How far a tonne goes

Approximate compacted coverage for one tonne of granular sub-base or capping at common build-up depths. Useful for sanity-checking a figure before you order.

Compacted depth	Coverage per tonne	Typical application
50 mm	≈ 10 m²	Regulating layer, thin topping
100 mm	≈ 5 m²	Footpaths and patios
150 mm	≈ 3.3 m²	Domestic driveways, cars and light vans
200 mm	≈ 2.5 m²	Yards and vehicle-trafficked areas
250 mm	≈ 2 m²	Capping over weak formation, haul roads

Order the material

Full specification, typical uses and lead times for the lines this calculator covers:

Calculator FAQs

How do I work out how many tonnes of aggregate I need?: Multiply the area in square metres by the depth in metres to get cubic metres, then multiply by the material's bulk density in tonnes per cubic metre. Most compacted sub-base materials sit around 1.9–2.0 t/m³, sands around 1.5–1.6 t/m³ and screened topsoil around 1.4 t/m³.
What depth of MOT Type 1 do I need?: As a general guide, 100mm compacted for footpaths and patios, 150mm for domestic driveways, and 200mm or more for vehicle-trafficked yards and access roads. Always follow the engineer's detail where one exists — subgrade condition changes the answer.
Should I add an allowance for compaction?: Yes. Loose material reduces in volume once compacted, so add roughly 10–15% on granular sub-base and capping layers. The calculator below lets you add a waste and compaction allowance.
How many tonnes are in a tipper load?: Around 12–13 tonnes in a 6-wheeler, 19–20 tonnes in an 8-wheel rigid tipper and 28–29 tonnes in an artic bulk tipper. Buying in full loads is usually the most efficient way to take bulk material.
Is the calculator accurate enough to order from?: It gives a sound working estimate for planning. Densities vary with moisture and source, and site conditions vary, so send us the figures with your enquiry and we will sanity-check them against the drawing before anything is loaded.

Everything you need to spec, price and move material — tools, services and the exact material pages they relate to.