How this planner works
Every number above comes from a few simple formulas. Here they are, so you can check them by hand.
- Pavers. Patio area × (1 + waste) ÷ area of one paver, rounded up. Waste is 5% for running bond and stack bond, 7% for basket weave, 10% for herringbone, plus 5% more for a circle because every edge paver is cut.
- Base gravel. The base extends 6" past every edge. Base area × depth in inches ÷ 12 ÷ 27 gives cubic yards; the planner then adds 15% because crushed stone compacts. Tons use about 1.4 tons per cubic yard, a typical figure for crushed stone. Bags assume 0.5 cubic feet each.
- Bedding sand. A 1" screeded layer over the patio area, plus 5%, at about 1.35 tons per cubic yard.
- Edging. The patio's perimeter in 8-foot pieces, with roughly one spike per foot.
- Dig depth. Base depth + 1" sand + paver thickness. Dig this far below where you want the finished surface, and slope the patio slightly away from the house so water drains off.
Reference guidance:Belgard paver installation and base guidance. Confirm material coverage and specifications with your supplier.
Worked example: a 12×12 patio
A 12-by-12-foot patio of 6"×9" pavers in running bond, on a 6" base:
- Area: 144 sq ft. The 5% allowance gives 151.2 sq ft before rounding. Order 404 pavers (151.5 sq ft).
- Base: 13 × 13 ft (the 6" overhang on each side) at 6" deep, plus 15% for compaction = 3.6 cubic yards, about 5.04 tons.
- Sand: 0.47 cubic yards of bedding sand, about 26 bags.
- Edging: 48 ft of perimeter = 6 pieces and about 48 spikes.
- Dig: 6" + 1" + 2⅜" = 9⅜" deep, over a 13 × 13 ft area.
Before you dig
Frequently asked questions
How many pavers do I need for a 12×12 patio?
A 12×12 patio is 144 square feet. With 6"×9" pavers in a running bond and 5% extra for cuts, you need about 404 pavers. Smaller pavers or a herringbone pattern push that number up; enter your own paver size above for an exact count.
How deep should the gravel base be under a paver patio?
A common starting point is 4 inches of compacted base on firm, well-drained soil, 6 inches for a typical patio, and 8 inches or more on clay or soft ground. Driveways need more again, often 8 to 12 inches. Your local supplier or building department can tell you what works on your soil and climate.
Why does the planner order extra gravel?
Crushed stone base compacts when you run a plate compactor over it, so a 6-inch compacted layer starts out deeper. The planner adds 15% to the base volume and extends the base 6 inches past the patio edge on every side, which is where the edging spikes sit.
How much polymeric sand do I need?
Coverage depends on the paver size, joint width and paver depth, and varies a lot by brand. The planner uses a rough figure per bag for each paver size. Always check the coverage chart on the bag you buy, and buy one spare bag.
Should I buy gravel in bags or in bulk?
Bags are convenient for very small jobs. Once you need more than a cubic yard or so, bulk delivery by the ton is usually much cheaper and far less lifting. The planner shows both so you can compare prices from your local stores and suppliers.