Paver calculator
A 12 × 12 ft patio of 4 × 8 in pavers takes 713 pavers with 10% for cuts, 5.07 tons of gravel for a 6 in compacted base and 0.44 cubic yards of bedding sand.
How many pavers
Divide 144 by the paver's length × width in inches to get pavers per square foot, then multiply by the area. Paver sizes are nominal and include the narrow joint, so the count comes out right. Add extra for cut pieces at the edges: a simple straight layout needs the least, and diagonal or herringbone patterns need the most.
Area: 12 ft × 12 ft = 144 sq ft
144 ÷ (4 × 8) = 4.5 pavers per sq ft × 144 sq ft × 1.1 = 713 pavers
| Paver size | Pavers per sq ft | Per 100 sq ft with 10% |
|---|---|---|
| 4 × 8 in | 4.5 | 495 |
| 6 × 6 in | 4 | 440 |
| 6 × 9 in | 2.667 | 294 |
| 12 × 12 in | 1 | 110 |
| 16 × 16 in | 0.563 | 62 |
| 12 × 24 in | 0.5 | 55 |
| 24 × 24 in | 0.25 | 28 |
Base and bedding
Pavers sit on a 1 in bed of coarse sand over a compacted gravel base. Unilock's installation guide gives these base thicknesses, using ¾ in crusher run or ¾ in clear stone:
| Use | Compacted gravel base |
|---|---|
| Patios | 6 to 8 in |
| Walkways | 6 to 8 in |
| Pool decks | 6 to 12 in |
| Driveways | 10 to 14 in |
Clay soil needs a deeper base and sandy soil less, so ask your paver supplier what they recommend for your ground. The calculator weighs the base as compacted crusher run at 1.9 tons per cubic yard, the middle of the Wisconsin DOT's range of 1.75 to 2.1, and the sand as loose sand at 2,700 lb per yard.
How deep to dig
Add the base, the 1 in of sand and the thickness of the pavers. A patio with a 6 in base and 2⅜ in pavers needs a dig of about 9⅜ in below the finished surface, plus any slope you build in for drainage.
Sources
- Basic Technical Guide: pavers and walls, Unilock, January 2024. Gravel base of 6 to 8 in for patios and walkways, 6 to 12 in for pool decks, 10 to 14 in for driveways; a 1 in bed of coarse sand; 6 in of base under walls.
- Weight-Volume Relationships and Conversion Factors for Soils and Aggregates of Wisconsin (WHRP 0092-22-05), Wisconsin Highway Research Program, Michigan State University, December 2023. Measured loose and compacted weights of base aggregates, recycled asphalt and recycled concrete; tons per compacted cubic yard.
- Highway Maintenance Tables and Conversion Factors (Engineering Policy Guide appendix), Missouri Department of Transportation, current guide. Loose and compacted weights of crushed stone, sand, asphalt and concrete in pounds per cubic foot and per cubic yard.