That old couch from your great-grandmother's estate may not seem all that special, but if you're using it, you could be sitting on a small fortune. Of course, qualifying as an antique doesn't guarantee that something is worth much money--its value could be strictly sentimental. That doesn't mean you shouldn't check to be sure. Though a genuine appraisal requires the help of a trained professional, there is a bit of legwork you can do yourself.
Signs of Age
Feel the edges of the couch's frame--sharp corners and edges are a hallmark of modern furniture. This could be your first clue.
Check underneath the couch for any tags indicating the furniture manufacturer, upholsterer or year of production. Should you find any information, look it up in a furniture price guide such as "Kovels' Antiques & Collectibles Price Guide 2010." These guides usually provide estimates, though--not exact figures.
Carefully remove a screw from the couch if you can find one. Older screws have irregular spacing between the grooves. Modern screws have the sharply pointed, uniform look.
Gauging Value
Check for ornate design features. For example, furniture with curved legs or carved, clawed feet is generally more valuable than plain, straight-legged furniture.
Gently scratch through the paint if the wood appears painted. If there are several layers of paint, the piece may have depreciated in value.
Consult a trained appraiser. Before taking your couch to the appraiser, find out how much he will charge for the appraisal. An appraiser's services can be expensive. Use the link in the Resources section to find an appraiser near you who can gauge your couch's worth.