Project planning guide
Paver Base Depth Guide
Plan compacted aggregate base depth for patios, walks, and driveways based on soil, drainage, climate, and loads.
Written by Groundwork Calculators · 13 min read · Last reviewed September 19, 2026
Base depth means compacted depth
A paver section normally includes subgrade, compacted aggregate, thin bedding, and pavers. The calculator input describes finished compacted aggregate—not loose pile depth or total excavation.
Excavation must also accommodate paver thickness and bedding. Equating excavation depth with base depth can leave the surface too high.
Use ranges only for preliminary quantities
Manufacturer instructions and local requirements take priority.
| Application | Early-planning range | Conditions that may require more |
|---|---|---|
| Pedestrian patio or walk | 4–6 compacted in (10–15 cm) | Weak soil, poor drainage, frost |
| Residential driveway | Often 8–12+ in (20–30+ cm) | Vehicle load, weak soil, freeze-thaw |
| Bedding layer | Often about 1 in (2.5 cm) | Follow the paving-system specification |
Let site conditions control the section
Firm, drained subgrade differs from saturated clay or recent fill. Correct soft spots and water problems before aggregate; simply adding gravel over unstable soil may not prevent movement.
Extend base beyond the paver edge to support restraint. Include that extension in base area even though it is outside visible paving.
Place and compact in lifts
Multiple thin lifts compact more evenly than one deep layer. Allowable loose lift thickness depends on material and equipment. Confirm moisture and lift requirements.
Six compacted inches across a 15 ft by 12 ft patio equals 90 cubic feet, or 3.33 cubic yards, before edge extension and allowance.
Estimate materials separately
- Calculate aggregate base at compacted depth
- Estimate bedding sand separately
- Estimate pavers from surface area plus cutting allowance
- Do not use allowance as a substitute for subgrade repair or unknown compaction
Worked patio section
For a 15 ft × 12 ft patio, the visible paving is 180 sq ft. With a 6-inch base extension on every edge, the aggregate footprint becomes 16 ft × 13 ft, or 208 sq ft. At 6 inches compacted depth, the base occupies 104 cu ft (3.85 cu yd) before allowance.
A separate 1-inch bedding layer under the visible 180 sq ft occupies 15 cu ft (0.56 cu yd). If the pavers are 2⅜ inches thick, approximate excavation depth is 6 + 1 + 2⅜ = 9⅜ inches, plus any project-specific grade correction. The Paver Base Calculator keeps those three depths distinct.
| Part | Input | Result before allowance |
|---|---|---|
| Visible paving | 15 ft × 12 ft | 180 sq ft |
| Extended aggregate base | 16 ft × 13 ft × 6 in | 3.85 cu yd |
| Bedding | 15 ft × 12 ft × 1 in | 0.56 cu yd |
| Excavation section | 6 in + 1 in + 2⅜ in | 9⅜ in |
Put the numbers to work
Use the related calculator to turn your measured area and planned depth into a material estimate. Then confirm the final order with the product supplier.