Measure the area with the tape measure to get an idea of the size area rug you will need. Keep at least 1 foot of floor space around the outer area of the rug to allow the flooring beneath the rug to show. The contrast will create a gorgeous effect around your area rug.
Examine the space to ensure the furniture will sit properly above the space you plan for the area rug. If there is seating over the area rug, the rug must be large enough so that all chairs will stay on the area rug even when people are sitting in the chairs, as a rug placed under a dining room table and chairs, for example.
Create an outline of the area you think you want to cover with the area rug using masking tape. Apply pieces of masking tape onto the floor so you can visualize the area you plan to cover. Look at the outline carefully to ensure you are completely happy with it.
Measure the masking tape outline with the tape measure when you are sure the tape outlines the dimensions you desire for an area rug. Measure the length and width. Write these dimensions down so you will remember them as you shop for an area rug.
Formulate a size range in case you cannot purchase an area rug with the exact dimensions you measured in step 4. Determine what size would be the smallest acceptable area rug size and what size would be the largest acceptable area rug size for a rug to fit properly into your space.