Aside from the legs being scratched, worn and ugly, there are other good reasons for replacing them. Just like changing your shoes can change the look of your outfit, replacing your sofa's legs can alter the look of your room and sofa. You can take a traditional sofa and give it a more contemporary feel by inserting either a higher, tapered dark-wood or metal sofa leg. You can do all this at amazingly low cost: from 80 cents to about $10 per leg at time of publication.
There are almost as many types of sofa leg styles, according to mounts and heights, as there are sofas. The basic categories are hanger bolt, screw mount, metric and dowel mount. The hanger bolt, the easiest to replace, has screws on top that insert into premounted T-nuts. Sometimes, you have to replace these as well, but it's not difficult to do. Simply, use your hands to turn the leg.
Instead of bolts coming out of the top of the leg, there are holes drilled into the leg to receive the screws that come with the package. This style of leg is relatively easy to install. After turning over the sofa and removing the old legs, simply screw the new legs into place. This type of leg is limited in height. so you need to consider the surface on which the sofa sits. If it's a deep pile carpet, your sofa may look like it's drowning.
Most metric sofa legs originate in Europe, hence the metric measurements. Available in metal and metal finish and a variety of heights, they give a more modern look to a sofa. A distinguishing characteristic of the bolt is that it is only 3/8 inch. These, too, are easy to mount onto your old sofa. Not too common are the dowel-mount legs, which consists of a leg with a dowel on the top that inserts into predrilled holes in the bottom of the sofa.
Decide how high off your floor you want to be -- from 1 to 12 inches. Take into account the surface of the floor, the sofa style and the size of the people using it. Measure the height from the floor to the top of the sofa cushion. Add 1 inch or so to allow for a deep pile. More modern sofas, with their deep seats, take a lower leg. More traditional sofas have less deep seats, so if the legs are too low, people's knees will be at their chins.