How to Calculate Yardage for a Landscape

Correctly calculating or approximately estimating the area of a lawn, garden, flower bed or other feature will help you to better plan and implement projects. Knowing the area or volume of a space in square or cubic feet allows you to obtain enough material for the task, eliminating the need for excessive trips to the store or a second order placed with a supplier. This will ensure you do not order too much material, a potentially costly error.

When planning an overall landscape design or estimating the quantity of a material like sod or mulch that you will need to complete a project, it is helpful to draw a diagram of the landscape. Divide the section you want to know the area or volume of into simple geometric shapes like rectangles and triangles. Then, measure each of these subsections separately and record their dimensions. For rectangular areas, measure two adjacent sides. For a triangular section, measure one side, the base, and then the distance between the point opposite the base and where the measuring tape hits the base at a 90-degree angle. If you measure the dimensions of these subsections in feet, you can divide the measurements by three to convert them to yards.

To calculate the area of a rectangular section, multiply its length by its width. In other words, multiply the dimensions of two adjacent sides of the rectangle. To determine a triangle's area, multiply its base and its height and then divide the resulting number by two. To determine the total area of the yard or landscape you diagrammed, add the areas of the indivdual subsections together.

If you are calculating cubic yardage, you must take an additional dimension, height or depth, into account. For example, if you are applying wood chips or another mulch material, you will need to known the volume of material required. To do this, multiply the site's area by the planned depth of material. Make sure that your units of measurement are the same when making calculations. For example, if you want to determine how many cubic yards of mulch you need to cover a 15 square yard area with 3 inches (3/36 yard) of mulch, you will have to multiply 15 square yards by 3/36 yard to determine that you need 1 1/4 cubic yards of mulch to complete the task.

When ordering sod, mulch or another material, round up when you are making your calculations and, in the case of sod, plan to order at least an extra 5 percent to 10 percent of material to account for trimmings, miscalculations, unhealthy sod pieces and handling errors. If you are ordering sod, check with your supplier to see how much sod comes on a pallet. Sod is often available only in pallets of 50 or 75 square yards. Other materials may be sold by weight or by truckload, so obtain conversion rates from each supplier.