Throws are often kept on sofas merely as a convenient spot for a blanket, but they can also serve as decoration. When it comes time to choose a throw for a sofa, one of the most important aspects to consider -- aside from the colour pattern -- is the size. Since throws should fit each person's individual style, there is no right or wrong way to choose a size. Any possible problems which may arise from choosing a throw size are generally easy to work around.
Look at the sofa and picture how wide you want the throw to be. Some common choices are the distance between the armrests, the width of one sofa cushion or half the width of the sofa.
Hold a tape measure against the top of the sofa. Imagine your ideal size of throw on the sofa and measure the distance from one side to the other. Write the measurement down on a sheet of paper.
Browse home furnishing stores -- either in person or on the Internet -- and compare your desired throw size with the dimensions of throws that fit your style. Keep in mind that it is possible that you won't find a throw with the exact measurement you hope for. In such cases, choose a size that is slightly larger than what you need as you can either shrink the throw in the wash, bunch it up on the sofa or hem it along one side.