Measure the vertical and horizontal distances of the patio you intend to cover with brick paver. Write down these measurements on the top of your graph paper. If the patio is an unusual shape (other than square or rectangle), be sure to take a measurement for each side of the area.
Using the graph paper, sketch out the shape of the patio using the grid lines to provide some sort of scale (e.g. each grid should represent 6 inches or 12 inches). The drawing does not need to be perfect; it will be used for your reference as to which side each measurement is assigned. Label each segment with the measurements taken in Step 1.
Calculate the total area of the patio. If it is a rectangular shape this is done by multiplying the vertical and horizontal measurements. If it is an odd shape, use the drawing you made to divide the area into manageable quadrants. For example, break down the area into either triangles or squares so the area can be easily calculated. Don't worry if a piece does not fit perfectly into a triangle or square shape. The estimate needs only to be close, not perfect. Once you have all the areas of quadrants, add them together to receive a total.
Determine the brick type you will use for paving and make note of its dimensions and cost per brick. You can accomplish this at a local home and garden supply store or through your contractor. Big box home improvement stores can typically order more varieties than they carry in stock. If you are using a contractor, ask him to bring over samples of bricks to choose from.
Multiply the length and width of the brick together to obtain its area. Ensure that the measurement of the space is in the same unit as the area measurement for the brick. Most likely both measurements should be in inches. Divide the total area by the area of a single brick. This resulting number will be the number of bricks you will need to complete the project. Multiple this quantity by the cost per brick. This total will be your estimated cost for the project.
If you are completing the project yourself, add the cost of cement to obtain the total. Your local hardware store can provide the amount of cement necessary for your given area. Bags of cement are relatively inexpensive, $5 for a 40-pound bag, and will not be a significant change to the estimate. If you are having a contractor complete the project, get a labor cost to add to this material cost for the true total.