Paver Calculator

Tip: extend the gravel base 6 inches past the edge of the pavers on every side. The edge restraint needs solid ground to sit on, or the border pavers will creep outward.

Worked example

A 12 ft by 12 ft patio is 144 square feet. A standard 4 x 8 inch brick paver covers 32 / 144 = 0.222 square feet, which works out to 4.5 pavers per square foot.

Adding 10% for cuts brings the area to 158.4 square feet, and 158.4 / 0.222 = 712.8, so you buy 713 pavers.

Under them, a 4 inch gravel base takes 1.78 cubic yards, about 2.5 tons, and a 1 inch layer of bedding sand takes 12 cubic feet, or 24 bags of 0.5 cubic feet.

How to calculate pavers

Find the patio area in square feet by multiplying length by width. Find the area of one paver by multiplying its length and width in inches and dividing by 144. Divide the patio area plus a waste allowance by the area of one paver and round up.

Many pavers are sold by the square foot or by the pallet rather than by the piece. In that case, skip the paver count and order the square footage with waste. A pallet commonly covers 80 to 120 square feet, so ask your supplier.

Common paver sizes

• 4 x 8 inch brick or holland: 4.5 per square foot.
• 6 x 6 inch: 4 per square foot.
• 6 x 9 inch: about 2.7 per square foot.
• 12 x 12 inch: 1 per square foot.
• 16 x 16 inch: about 0.56 per square foot.

Patterns that mix sizes, like an ashlar or random pattern, are sold as a set by the square foot. Use the coverage on the product sheet.

How much waste to allow

Use 5% to 10% for a running bond or stack pattern on a rectangular patio. Herringbone patterns and curved edges need 10% to 15% because many border pavers are cut. A soldier course, a row of pavers turned sideways along the edge, adds a nice finish and reduces small cuts at the border. Keep a few spare pavers for future repairs.

Base and bedding layers

Pavers need a solid, well drained base or they will sink and shift. The standard build-up is:

• Excavate to the depth of the base plus sand plus the paver thickness, usually 7 to 9 inches for a patio.
• Lay 4 to 6 inches of crushed stone base, compacted in 2 inch layers with a plate compactor. Driveways need 8 to 12 inches.
• Screed a 1 inch layer of coarse concrete sand. Do not compact it before laying pavers.
• Lay the pavers, install edge restraints, then sweep in joint sand and compact the surface.

Compacted base shrinks, so many installers order 10% to 20% more base stone than the finished depth suggests. The gravel calculator can size it at any weight per yard.

Joint sand and edging

Polymeric joint sand locks pavers together and resists weeds and ants. Coverage depends on paver size and joint width, often 30 to 100 square feet per 50 lb bag. Narrow joints between rectangular pavers use less, and tumbled pavers with wide joints use more. Edge restraint is sold in lengths: measure the perimeter of any edge not held by a wall or slab.

Planning the layout

Before you order, mark the patio outline with stakes and string or marking paint and live with it for a day or two. Check that furniture fits with room to walk around it. A dining table and chairs needs at least 12 by 12 feet, and a fire pit area about 14 by 14. Plan a slight slope away from the house, about 1/4 inch per foot, so water drains off the surface.

More calculators

Results are estimates, not a contractor quote. Check quantities with your supplier before you order, and follow local building codes.