Gravel Base Calculator
Estimate compacted base volume, loose aggregate volume and approximate delivery tonnage for paving foundations, driveways and sub-bases.
Project Measurements
Choose your unit system and enter finished base dimensions.
Material Assumptions
Enter compaction loss and loose bulk density.
Planning estimate only. Actual aggregate volume and weight depend on grading, moisture, density, compaction and site conditions.
Your Estimate
Calculate to display compacted and loose quantities.
How It Is Calculated
Gravel is normally delivered loose and compacted on site. The 10–20% loss allowance is a planning starting point — confirm the correct compaction factor with your supplier or project guidance, since it varies with aggregate type, grading and moisture.
What This Gravel Calculator Estimates
Base area, geometric compacted volume, estimated loose delivery volume after accounting for compaction, and approximate material weight using loose bulk density. Supports US customary and metric units.
Before You Order Aggregate
Confirm grading, compaction factor, moisture content and delivery minimums with your supplier. Local truckload quantities and site access can affect the practical order size — this is a planning tool, not a spec sheet.
How to Estimate Gravel Base Materials
Aggregate base material is normally delivered in a loose state and compacted in place to form the foundation for pavers, asphalt or concrete. Because loose volume shrinks during compaction, ordering directly from the finished geometric volume would leave you short. The correct estimate needs three things: base dimensions, compacted depth and a reasonable compaction allowance.
1. Measure the Finished Base Footprint
Multiply base length by width to get the surface area. For irregular foundations, split the area into rectangles and add the sections. Allow a small extra margin around the paved edge if the base extends past the finished surface.
2. Choose the Compacted Depth
Pedestrian paths typically use 4 inches of compacted base; driveways usually need 6 inches or more; heavy vehicle areas may require deeper layers. Depth depends on soil conditions, drainage and expected loads — confirm the required thickness with local codes or a paving contractor.
3. Apply a Compaction Allowance
Loose aggregate compacts to a smaller volume after grading and rolling. A 10–20% allowance is common, though the correct figure depends on aggregate type, particle shape and moisture. Suppliers often provide a compaction factor — use it when available.
4. Convert Loose Volume to Weight
Gravel is sold by weight (US short tons or metric tonnes) in most regions. Multiply the loose volume by loose bulk density, then convert: divide by 2,000 for US short tons (lb/cu ft × ft³), or by 1,000 for metric tonnes (kg/m³ × m³). Bulk density varies from around 100 lb/cu ft for some lightweight materials to over 130 lb/cu ft for dense crushed stone.
5. Verify Delivery and Site Access
Trucks deliver in fixed-capacity loads. Confirm delivery minimums and site access with your supplier so the planned order matches truckload quantities and storage space. If you are ordering multiple aggregate layers (sub-base, base, bedding), calculate each layer separately.
Frequently Asked Questions
Is 15% loss always the correct allowance?
No. It is a planning starting point, not a universal compaction factor. The correct value depends on aggregate type, grading, moisture and required finished density. Use supplier or project-specific guidance when possible.
Why can aggregate weight vary for the same volume?
Rock type, particle size distribution, moisture content and loose bulk density all affect delivered weight. Use a density value appropriate for your specific material.
Should I order by volume or by weight?
Most gravel suppliers quote by weight (US short tons or metric tonnes). Some quote by volume (cubic yards or cubic metres). This calculator gives you both so you can compare quotes.
Can I use metric measurements?
Yes. Select Metric to enter length and width in meters, depth in millimeters and density in kg/m³. Area is shown in m², volumes in m³ and weight in metric tonnes.
What is a US short ton?
A US short ton equals 2,000 pounds. Confirm the unit your supplier uses when comparing quotes or delivery quantities.