Paver Base Calculator: How to Build a Stable Paver Patio
How much gravel and sand for a paver patio or walkway. Calculator guide, base depth requirements, and installation tips.
The long-term performance of any paver installation — patio, walkway, or driveway — depends almost entirely on the quality of the base. Pavers themselves rarely fail; bases do. Getting the base depth and materials right is the most important decision in any paver project.
The Three-Layer System
A proper paver installation has three layers:
- Compacted subgrade — natural soil, compacted and properly graded
- Aggregate base — crushed stone, compacted (4–8” depending on application)
- Bedding sand — 1” of coarse sand for final leveling
Base Depth Requirements
| Application | Aggregate Base | Bedding Sand | Total Excavation |
|---|---|---|---|
| Foot traffic patio | 4–6” | 1” | 5–7” + paver thickness |
| Light vehicle (parking) | 6–8” | 1” | 7–9” + paver thickness |
| Driveway (passenger car) | 8–12” | 1” | 9–13” + paver thickness |
Use our Paver Base Calculator to calculate gravel and sand volumes.
Calculating Base Materials
Gravel volume (cubic yards) = (Length × Width × Depth in feet) ÷ 27
Sand volume (cubic yards) = (Length × Width × 1 foot/12) ÷ 27
Example: 16×20 ft patio, 6” gravel base, 1” bedding sand:
- Gravel: (16 × 20 × 0.5) ÷ 27 = 5.93 cubic yards
- Sand: (16 × 20 × 0.083) ÷ 27 = 0.99 cubic yards ≈ 1 cubic yard
Add 10% for gravel compaction and waste.
Aggregate Base Material Selection
Use 3/4” compactable crushed stone (sometimes sold as “road base,” “crusher run,” or “3/4” minus”). This material compacts to a dense, stable surface because the angular pieces lock together.
Warning — What NOT to Use: Round pea gravel, river stone, or clean 3/4” stone without fines will not compact properly and will shift under load. Pavers installed over these materials rock, sink, and create trip hazards within one or two seasons. If your supplier doesn’t carry crusher run, ask for “3/4 minus” or “compactable base gravel” — these are the same product by different regional names.
Bedding Sand
Use coarse concrete sand (also called ASTM C-33 sand). Fine play sand or polymeric sand is not suitable for bedding.
The bedding layer should be exactly 1 inch — not more. Excess sand causes pavers to rock and settle unevenly.
Compaction
Compact the aggregate base in 3-4 inch lifts using a plate compactor (rental: $60–$90/day). Pass the plate compactor over each lift until the stone doesn’t move. A properly compacted base won’t show tire marks from a car.
Don’t compact the sand layer. It’s meant to be a loose screeding layer that you level precisely before placing pavers.
Frequently Asked Questions
Do I need to add a weed barrier under pavers? Between the aggregate base and bedding sand, a permeable geotextile fabric helps prevent weed growth without impeding drainage. It’s optional but often worth doing for lower-maintenance results.
How many pavers do I need? Paver count = Area ÷ Individual paver area × 1.10 (waste factor). For a standard 4”×8” brick paver: 4.5 pavers per square foot.
Can I use polymeric sand for bedding? No — polymeric sand is for filling joints between pavers after installation. Use coarse concrete sand for the bedding layer, then apply polymeric sand to the joints once pavers are placed and leveled.
What happens if I don’t compact the base? The base will settle unevenly under load and over time. Individual pavers will rock, sink, and create tripping hazards. The base is the most important part of any paver installation.
See also: Excavation Calculation Methodology — volume formulas, bulk density tables, swell/shrink factors, and OSHA trench safety references behind ConstructCalc excavation calculators.
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