How this calculator works
It divides the patio area, plus a waste allowance for cuts and breakage, by the face area of one paver. Joints are left out because pavers are laid tight, with only a sand-filled hairline between them.
Under the pavers it adds a compacted crushed-stone base, sold by the ton (1.4 tons per cubic yard by default; 1.6 t/m³ in metric), and a bed of sand in bags (1″ by default, 3 cm in metric), each with 10% extra for compaction. Metric sand bags are sold by weight, so the count uses 1.6 tonnes per cubic metre of dry sand.
pavers = length × width × (1 + waste) ÷ (paver length × paver width)
base tons = area × base depth ÷ 12 × 1.1 ÷ 27 × density
sand bags = area × sand depth ÷ 12 × 1.1 ÷ cu ft per bagWorked example
A 12′ × 10′ patio is 120 sq ft. An 8″ × 4″ paver covers 0.222 sq ft, so it takes 4.5 per sq ft; with 5% waste that is 567 pavers. A 4″ base is 40 cu ft, 44 cu ft with compaction: 1.63 cu yd, or 2.28 tons at 1.4 tons per cu yd, so you order 3 tons. The 1″ sand bed is 11 cu ft, which is 22 bags of 0.5 cu ft.
Tips before you buy
- Use the actual paver size from the product label, not the nominal size; it changes the count.
- Herringbone and patterns laid at 45° need more cuts. Raise the waste to 10%.
- Dig out enough to fit base, sand and paver thickness, and slope the surface away from the house for drainage.
- Edge restraints along open sides keep pavers from creeping apart; buy them by the perimeter length.
- Joint sand (regular or polymeric) is a separate product; its coverage depends on joint width, so check the bag.
Questions
- How many pavers per square foot?
- Divide 144 by the paver’s length times width in inches. An 8″ × 4″ paver works out to 4.5 per sq ft, a 6″ × 6″ to 4, and a 12″ × 12″ to 1.
- How deep should the base be under pavers?
- Four inches of compacted crushed stone is common for patios and walkways. Driveways and soft or clay soils usually need 6 to 8 inches or more, so follow the paver maker’s instructions for your use.
- How much waste should I allow for pavers?
- Five percent covers cuts and the odd broken paver on a simple rectangle in a running bond. Herringbone, diagonal layouts and curved edges create more offcuts, so allow 10% or more.