You will need to know how to measure a sofa before you buy it, since you need to be sure that it will fit into your space. you also need to measure it to know if you will be able to take it through your entry and any other passages before you place it in the desired room. Here is what you need to measure:
Width:Measure the width from arm to arm. Make sure that you are taking the width measurements at the widest point of the sofa. For instance, if the sofa has rolled arms, measure from outside the widest part of one arm to the other arm, and not at the bottom near the legs.
Height:Measure the height. Again, measure at the highest point. For instance, a camelback sofa will be highest in the center.
Depth:Measure the depth of the sofa from the outside edge of the seat all the way to the back.
Diagonal Depth:Measure the diagonal depth of a sofa by placing a straight tape measure from the top back of the frame to the bottom front.