Tons of compacted road base under patios and driveways
This aggregate base calculator converts the area and thickness of your base layer into cubic yards of material and tons to order, using the compacted density of the product you select. It is built for patios, driveways, walkways, and other hardscape projects where a stable, compacted base layer is the difference between a surface that lasts decades and one that fails in a season.
The math is simple but easy to get wrong by hand: volume in cubic feet equals length × width × depth (in feet), divide by 27 to get cubic yards, then multiply by the material's density in tons per cubic yard. Compacted road base weighs roughly 1.4 tons per cubic yard, so a small rounding error in volume becomes a real error in tons ordered — and quarry minimums and delivery fees make both over- and under-ordering expensive.
Enter your project dimensions and the compacted thickness your detail calls for. Common specs are 4 inches under paver patios and walkways on decent soil, and 6 inches under residential driveways. The calculator computes tons = yd³ × density, where compacted road base is about 1.4 tons/yd³.
Two details matter in practice. First, you order loose material but achieve a compacted volume — base rock compacts roughly 15–20% by volume, so a loose pile shrinks as it is compacted in lifts. Second, a small waste factor (about 5%) covers uneven subgrade and edges. If you skip the compaction step or try to compact one deep lift instead of 2–3 inch lifts, the layer will settle later and the surface above will follow it.
Densities vary by product and gradation. The table below shows the typical compacted weights used for ordering, plus the loose weight you may see on a quarry ticket. When in doubt, ask the supplier for the density of the specific product — crushed stone products commonly run 1.35 to 1.5 tons per cubic yard depending on gradation.
| Material | tons/yd³ | lb/yd³ | Notes |
|---|---|---|---|
| Class II aggregate base (compacted) | 1.4 | 2,800 | Standard under pavers and asphalt |
| 3/4 in crushed stone | 1.35–1.5 | 2,700–3,000 | Depends on gradation and angularity |
| Road base, loose in the truck | ~1.25 | ~2,500 | Settles 15–20% when compacted |
| Recycled concrete base | 1.35–1.45 | 2,700–2,900 | Check for debris oversize |
Aggregate is sold by the ton at the quarry, with delivery priced per mile or as a flat zone fee. Small loads are the classic trap: a 4-ton order may cost nearly as much to deliver as 15 tons, so neighbors often combine orders. For a typical paver patio of a few hundred square feet at 4 inches, expect 3 to 5 tons; a two-car driveway at 6 inches runs roughly 14 to 15 tons per 500 sq ft.
At 4 inches compacted, one ton of road base covers about 58 sq ft; at 2 inches, about 116 sq ft. Have the base delivered as close to the work area as possible, spread it same-day, and compact each lift with a plate compactor before adding the next. Keep the base slightly wet during compaction — moisture helps particles lock together.
The layer under the base matters as much as the base itself. Excavate to firm, compacted subgrade — soft spots and unsuitable soil should be removed and replaced rather than buried, because a base bridge over a soft spot will eventually settle and reflect through the surface. On clay or consistently wet soils, a geotextile separation fabric between subgrade and base keeps the stone from gradually punching into the native soil and losing thickness.
Drainage is the other silent killer of base layers. Water pooled against or beneath base rock softens the subgrade and pumps fines through the stone, so grade the excavation to shed water and plan where runoff goes. Edge restraints — concrete curbing, plastic paver edging, or a soldier course — keep the compacted base from creeping sideways under load, which is a common failure at driveway aprons and patio edges.
How many tons in a cubic yard of road base?
Compacted base rock weighs roughly 1.4 tons (2,800 lb) per cubic yard; loose in the truck it is closer to 1.25 tons/yd³. Crushed stone products run 1.35–1.5 tons/yd³ depending on gradation.
How much does 1 ton of base rock cover?
At 4 inches compacted, one ton covers about 58 sq ft; at 2 inches, about 116 sq ft. For a two-car driveway at 6 inches, budget roughly 14–15 tons per 500 sq ft.
How thick should an aggregate base be?
4 inches is typical for patios and walkways on stable soil; 6 inches is standard for residential driveways. Poor draining clay soils often call for thicker base or geotextile fabric beneath it.
Do I compact base in lifts?
Yes — compact in 2–3 inch lifts with a plate compactor for each lift. A single deep lift will not reach the density that keeps the surface stable.
How do I convert cubic yards to tons?
Multiply cubic yards by the material's density: yd³ × 1.4 for compacted road base. For example, 3 yd³ × 1.4 = 4.2 tons; add about 5% waste and order 4.5 tons.