Aggregate Calculator

Enter your area and depth, pick your material, and get volume, weight, bag counts, and truckload estimates in seconds.

Typical depths: paths 2–3 in, driveways 4–6 in, drainage 6–12 in.

Editable. Common range: 1450–1950 kg/m³.

Extra volume to reach compacted depth.

Covers spillage and irregular edges.

For small projects only.

How to Calculate Aggregate for Any Project

Aggregate quantity comes down to three numbers: the area you're covering, the depth you need, and the density of the material. Multiply area by depth to get volume. Multiply volume by density to get weight. Add a compaction factor on top of that, because loose aggregate placed at 4 inches will settle to less than 4 inches once compacted, then add a waste buffer to cover spillage and edge irregularities.

This calculator runs that full chain. It converts your inputs to metric internally, applies compaction and waste as separate factors, then outputs volume in both cubic yards and cubic meters, weight in tonnes and short tons, bag counts, wheelbarrow loads, and truckload estimates, all in one pass.

Material Densities and When They Matter

Density varies more than most people expect across aggregate types. Road base sits at around 1,900 kg/m³ when compacted, which is nearly 25% denser than loose pea gravel at roughly 1,575 kg/m³. That difference directly affects how many tons your supplier will quote you. If your supplier gives you a specific density for their product, enter it in the density field; the preset values are typical starting points, not guarantees.

Material Typical Density Common Use
Pea gravel 1,550–1,600 kg/m³ Drainage, decorative beds, paths
Crushed stone (20mm) 1,600–1,750 kg/m³ Driveways, base layers, drainage
Road base 1,800–1,950 kg/m³ Sub-base under concrete, asphalt, pavers
River rock 1,550–1,650 kg/m³ Decorative, garden beds, dry creek beds
Masonry sand 1,450–1,600 kg/m³ Paver setting bed, mortar, levelling

Compaction vs. Waste: What's the Difference

These two factors are often confused but they do different things. Compaction accounts for the fact that loose aggregate occupies more space than compacted aggregate, so you need to order more material than your finished volume to achieve the target depth after compaction. A 10% compaction factor means the loose material will compact down to about 91% of its loose volume. Waste covers spillage during delivery and installation, offcuts at edges, and small overages for irregular shapes. Both factors are applied to your order total, and both should be included for any base layer project.

Bags vs. Bulk Delivery

Small bags (20 kg, 40 kg, 50 lb) are practical for repairs, small garden beds, and areas without vehicle access. Bulk bags (1 tonne each) work well for jobs in the 1 to 5 tonne range where a dump truck isn't practical. For anything over 5 tonnes, bulk delivery by the load almost always costs less per tonne than bagged material, and suppliers can tip the material directly where you need it. Use the bag count the calculator gives you as a sanity check: if you're looking at 80 small bags, bulk delivery is almost certainly cheaper.

Rough Material Costs

These are approximate US material-only costs. Delivery, compaction equipment, and labour are additional.

Material Cost per Ton (bulk) Cost per Bag (small)
Pea gravel $25 – $50 $5 – $9 (50 lb)
Crushed stone $30 – $55 $5 – $10 (50 lb)
Road base $20 – $45 Less common in bags
River rock $40 – $80 $6 – $12 (50 lb)
Masonry sand $20 – $40 $4 – $7 (50 lb)

Prices are approximate US averages as of 2025. Delivery cost often equals or exceeds material cost for loads under 5 tons.

Frequently Asked Questions

For any base layer that will be mechanically compacted, yes. Loose aggregate placed at 6 inches will typically compact to 5 to 5.5 inches, so you need to order extra to hit your target finished depth. For decorative surface applications like garden beds or dry creek beds where compaction isn't the goal, you can leave it at zero.
Use the preset for your material type as a starting point. If your supplier provides a spec sheet with a bulk density figure, enter that instead; it will give you a more accurate weight and bag count. For ordering purposes, rounding up to the nearest half-tonne is standard practice.
Once your order exceeds about 2 to 3 tonnes, bulk delivery almost always costs less per tonne than bagged material. The break-even point depends on your local supplier pricing and delivery fee, but if the calculator shows more than 50 small bags, it's worth getting a bulk quote to compare.

Aggregate Project Planning Checklist

Before ordering, confirm excavation depth, sub-grade condition, drainage slope, and delivery access to avoid costly surprises on the day.

Download Checklist (PDF)

Planning use only. See Methodology and Data Sources. View all project checklists →

Accuracy & Review

Reviewed by: Dave Whitaker

Dave is a second-generation paving contractor focusing on asphalt compaction, lift thickness, and milling yields for driveways and small parking lots. He reviewed the assumptions, calculation logic, and practical estimating guidance used in this calculator.

Last updated:

See: Methodology · Data Sources · Review Board

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Disclaimer

These calculations are general planning estimates only. Actual quantities may vary due to compaction rates, settlement, moisture content, material density variation, and site conditions.

Base preparation, drainage requirements, and load-bearing needs may alter total material requirements. Always confirm quantities with your supplier before ordering.

See our Methodology and Data Sources for details.