By Zencalcy Editorial TeamLast reviewed About us
Road base is a graded crushed aggregate compacted in lifts to form the load-bearing layer under asphalt, concrete or gravel. Because it compacts, the loose depth you place is deeper than the finished layer; this calculator adds 10% for settling and spillage.
Aggregate base quantity for a road, pad or drive.
V = L × W × D W = V × ρ Cost = V × price
Depth is entered in inches. Bulk density is taken as 1,760 kg/m³ (graded crushed aggregate base); real material varies with moisture and compaction, so treat the total as an estimate and add 5–10% for settling.
| Symbol | Meaning |
|---|---|
| L, W | Length and width of the area being covered. |
| D | Spread depth of the material. |
| V | Volume in cubic yards (and cubic metres). |
| ρ | Bulk density of the material. |
| W | Total weight, shown in pounds and US tons. |
1,200 sq ft at 6 inches gives 600 cu ft compacted; with the 10% allowance that is about 27 tons of road base.
Continue with the Asphalt Calculator, Crushed Stone Calculator, Gravel Driveway Calculator, or the Concrete Driveway Cost Calculator — or browse more driveways & paving and all construction calculators.
Six inches compacted for a residential drive, 8–12 inches for a road or heavy vehicle area, placed in 4-inch lifts.
Results use standard construction estimating arithmetic: volumes from measured area and depth, unit weights from published material densities, and code-referenced spans or clearances where the page names a code. Quantities are rounded up to whole saleable units and include the stated waste allowance. These tools are planning aids, not structural design, and do not replace a licensed engineer, a local code check, or a contractor's site measurement.
Reference material used to build and check this calculator:
Last reviewed: September 2026. See how we build and check every tool on the about page.
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Content updated: September 2026