To calculate the area in square yards of a square or rectangular shape, multiply the length by the width. If the dimensions of the shape are not given in yards, it is necessary to convert it first. An explanation for converting one unit to another is available from MathIsFun.com.

To calculate the area of a circle, first determine the radius. Next, enter the radius into a formula to find the area of a circle, which is pi multiplied by the radius and multiplied by the radius again. The value of pi is approximately 3.14. To find the area of a triangle, multiply the base by the height, and then multiply that product by 1/2.

In order to calculate the area of an irregular shape, take sections of the shape and superimpose regular shapes, such as squares and rectangles, onto them. Add those areas to approximate the area of the irregular shape, as explained by Basic-mathematics.com.

In order to convert the dimension to yards, determine what the conversion ratio is for that particular unit. For example, there are 36 inches in 1 yard. If the dimensions are given in inches, multiply each dimension by the quotient of 1 yard divided by 36 inches.