Patio pavers allow you to create a patio of nearly any size and shape. To figure out how many pavers you'll need, basic geometry formulas for calculating area will help. If your patio pavers have irregular shapes, rather than simple squares, rectangles, hexagons or octagons, you will need to calculate a rough estimate and adjust as necessary. The same goes for patios that are not basic geometric shapes. Most patio paver retailers list the square footage of each paver (or how many per square foot for small pavers), so you can base your calculations off the stated paver size. Note that all calculations are rounded to the nearest two decimal places.
Measure the length and width of your patio area for square or rectangle patios. Multiply these two numbers together and write down the result. This is your patio area square footage.
Measure the diameter (distance across the widest point) and divide it in half to determine the radius of circular patios. Multiply the radius by itself (for example, 5 feet times 5 feet), then multiply that number by 3.14, an approximation of the mathematical figure pi. This result is your round patio's square footage. You can also use this as an estimated area for hexagons and octagons, although the estimate will be slightly high.
Measure and multiply the radius of the short side by the radius of the long side for oval patios, then multiply your result by 3.14 for the square footage. Remember, radius is 1/2 the diameter.
Measure the base and height of triangular patio areas and multiply them together. Multiply this figure by 1/2 (.5 on a calculator) to determine the square footage.
Calculate irregular shapes by breaking them down into simpler shapes. Find the area of a rectangle that covers the entire patio area by measuring the length and width at the longest points and multiplying them together. Calculate the area of any triangles, rectangles or circles that aren't part of the patio using the formulas noted, and then subtract them from your total area.
Locate the square footage equivalent for each paver. If you are using small pavers, divide the number 1 by the number of pavers per square foot. For example, if four small pavers equal 1 square foot, 1 divided by 4 is .25 square feet.
Measure and calculate the paver size using the same formulas as for patio size, if the manufacturer does not list the paver square footage.
Divide your patio's square footage by the square footage of a single paver. For the small (.25 square feet) pavers noted and a 350-square foot patio, the calculation would be 350 divided by .25, which equals 1400 pavers. Covering the same patio area with pavers that are 1-square-foot each will require only 350 pavers (350 divided by 1).
Multiply your number of pavers by 1.1 to get the total number of pavers to purchase. This total will give you 10 per cent extra, which should cover lost area due to broken pavers or irregular shapes. If you calculated your area based on a high estimate, such as the overall circle encompassing a hexagon, this extra 10 per cent is not necessary.
If you plan to have space between pavers, calculate the paver square footage based on the paver size plus spacing. For example, if you are using 1-foot by 1-foot pavers (1 square foot each) but plan on having 1/2 inch of grout or sand between each paver, recalculate the paver area based on 1-foot plus 1/2 inch (0.042 feet) for the length and width. This means your formula is now 1.04 times 1.04, which equals 1.08 square feet per paver. Note that this adds spacing on only two sides, as the spacing added to the adjacent pavers will cover the other sides.