A paver patio needs 4 inches of compacted crushed stone base plus 1 inch of bedding sand. For the base: length × width × 0.33 ft ÷ 27 × 1.55 = tons. A 12 × 12 ft patio needs about 1.8 cubic yards (2.7 tons) of base stone and 0.44 cubic yards of sand.
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Order – tons (includes your waste allowance) so compaction and spillage don’t leave you short.
Paver Base Calculator Guide
Every failed paver patio fails from below. The pavers you see are only the top of a sandwich: compacted crushed stone doing the structural work, an inch of bedding sand doing the leveling, and the pavers riding on both. This calculator sizes the base layer — enter your patio’s dimensions at the default 4-inch depth and it returns the crushed stone in cubic yards and tons; run it again at 1 inch with sand selected for the bedding layer.
The 15% waste allowance matters more here than anywhere else: dense-graded base loses 10–15% of its depth to compaction, and a base that ends up thin at the edges is where pavers start their slow dive.
Base Depth by Application
| Application | Base depth | Per 100 sq ft (with 15%) |
|---|---|---|
| Walkway | 4 in | ≈ 2.4 tons |
| Patio | 4–6 in | ≈ 2.4–3.6 tons |
| Driveway (pavers) | 8–10 in | ≈ 4.8–6.0 tons |
| Cold climate + clay soil | add 2–4 in | +1.2–2.4 tons |
Excavation depth = base + 1 inch of sand + paver thickness (usually 2 3/8 in), measured down from finished grade. Dig the full footprint plus a 6-inch shoulder beyond the paver edge on open sides — the edge restraint needs base under it too.
The Build Sequence That Never Fails
- Excavate and compact the subgrade — the soil itself gets two passes before any stone arrives.
- Fabric on questionable soil. Woven geotextile keeps base and clay from trading places.
- Base in 2-inch lifts, each compacted with a plate compactor, checking slope as you go — 1 inch of fall per 8 feet, away from the house.
- Screed exactly 1 inch of concrete sand. Never level with extra sand; fix lows in the base itself (see the sand calculator for this layer).
- Lay, cut, restrain, and vibrate the pavers, then sweep polymeric sand into the joints.
Traditional Base or Open-Graded Base?
The build above is the traditional dense-graded method — crusher run compacted solid. The alternative gaining ground is the open-graded base: washed #57 stone with a #8/#9 chip layer instead of sand, which drains instantly and shrugs off freeze-thaw. It uses the same math with a different material selection. Whichever you choose, don’t mix the systems: a dense base wants sand bedding, an open base wants chip bedding, and swapping halves is how patios heave.
Frequently Asked Questions
How deep should a paver base be?
Use 4 inches of compacted crushed stone for walkways and patios, 6–8 inches for driveways, and up to 10–12 inches in cold climates with clay soil. The bedding sand on top is always a uniform 1 inch, never used to make up depth.
What material makes the best paver base?
Dense-graded crushed stone with fines — crusher run, #411, or paver base blend. It compacts into a rigid platform. An alternative for drainage-focused builds is an open-graded base of #57 stone topped with #8 or #9 chips instead of sand.
Do I really need to compact the base in lifts?
Yes — plate compactors only effectively compact about 2 inches at a time. Spreading and compacting two 2-inch lifts gives a far denser base than one 4-inch lift, and uneven compaction is the top cause of sunken pavers.
How much should the base extend beyond the pavers?
Extend the base 6 inches beyond the paver edge on all open sides. That shoulder supports the edge restraint and stops the outer pavers rotating outward under load.