Calculator

Patio and paver calculator

Enter the patio size and the paver you plan to use. The tool estimates how many pavers to buy, and how much crushed-stone base and bedding sand to order. It updates as you type, and nothing leaves your device.

How the calculator works

Each paver plus its joint takes up a small footprint. The tool adds the joint width to both sides of the paver, multiplies them, and divides into 144 square inches per square foot. That gives pavers per square foot. It multiplies by the patio area, adds your allowance for cuts and breakage, and rounds up to a whole paver.

For the base, it multiplies the patio length and width, each widened by the edge extension on both sides, by the base depth in inches divided by 12. The result in cubic feet is divided by 27 for cubic yards, then 10 percent is added for compaction and waste. The sand bed is worked out the same way across the patio area alone.

Worked example

A 12 ft by 10 ft patio is 120 square feet. With 12 inch pavers and an eighth inch joint, one paver covers 12.125 by 12.125 inches, or 1.021 square feet, so 120 square feet needs about 117.5 pavers. Add 10 percent and round up for 130. The base area including 6 inches of overhang on each side is 13 by 11 feet, or 143 square feet. At 4 inches deep that is 47.7 cubic feet, or 1.77 cubic yards, and with 10 percent extra that is about 1.94 cubic yards, rounded up to 2.0 for the order. The sand bed at 1 inch is 10 cubic feet, about 0.41 cubic yards with the allowance, rounded up to 0.5.

Where the layer depths come from

Paving industry installation guides, including those from the Interlocking Concrete Pavement Institute, describe patios and walks as a compacted aggregate base topped by a thin bed of bedding sand, commonly about 1 inch. A base depth of about 4 inches is a widely quoted starting point for foot traffic in stable soil. Soft or wet soil, frost, or vehicle loads need more, which is why the depth is an input you can change. Local conditions and the maker's instructions override these defaults.

How much extra to buy

Straight layouts with square pavers need little waste, around 5 to 10 percent. Curves, diagonal patterns, and patios with many corners cut more units, so raise the allowance to 15 percent or more. Buying all pavers from one lot at once avoids slight color differences between batches, and spares are useful for later repairs.

Weight estimates

The tonnage figures use rough densities of about 1.4 tons per cubic yard for crushed stone and 1.35 for sand. Real values depend on moisture and gradation, so treat them as a rough guide and ask the supplier. Never plan a vehicle load from this tool.

What it does not cover

The estimate leaves out edge restraints, geotextile fabric, polymeric or plain joint sand, drainage, and slope. A patio needs a slight fall away from buildings, commonly described as about 1/4 inch per foot, so water does not run toward a wall. Excavation depth should equal base plus sand plus the paver thickness, and you must plan for where the soil you dig up will go.

Where this comes from

The paver count uses simple area geometry. The layer depths follow common residential guidance from paving industry groups and extension and contractor resources that we read, and they vary by region and soil. This page is general information, not engineering or professional advice.

Go deeper

• Which hardscaping projects help a yard most
• Planning a yard so it works better
• Landscape materials buying guide