The aggregate base under pavers spreads loads and creates a stable platform. The right depth is not one universal number: it depends on project use, soil, drainage, climate and the paver system you are installing.
Compacted depth is the key number
When a specification calls for a base depth, it normally refers to the finished compacted layer. Loose aggregate occupies more volume before compaction, so material should be installed in manageable lifts and compacted as required by the project specification.
Planning ranges by project type
| Project | Planning consideration | Why it changes |
|---|---|---|
| Walkway | Usually lighter-duty | Mostly pedestrian loading |
| Patio | Moderate structural base | Furniture, foot traffic and local soil |
| Driveway | Heavier-duty design | Vehicle loads require stronger support |
| Freeze-thaw climate | May require additional preparation | Drainage and frost movement matter more |
Do not forget the full excavation depth
The aggregate base is only part of the build-up. Excavation also needs to account for bedding material and the paver thickness, plus any required slope for drainage.
Planning tipUse the compacted aggregate depth in the calculator, then confirm the final section with the paver manufacturer or local installation standard.
Common mistakes
- Calculating only the visible paver thickness.
- Using loose depth instead of finished compacted depth.
- Ignoring soft or poorly draining subgrade.
- Skipping local manufacturer guidance for driveways and difficult sites.