Things You'll Need
Instructions
Figure out how long you want your jeans to be. A good rule of thumb is to leave an inch between the hem and the ground when you are standing up straight. This step is a lot easier with a friend to mark or pin the jeans at the desired length while you are wearing them, but you can always use a measuring tape and basic math to figure out just where to pin. Always measure and make sure the length is even at all points around the leg before you proceed.
Trim the excess material. Leave about a 1-inch hem allowance, and cut an extra 1/2-inch from any existing seams. When you fold the material over, this extra cut will prevent the seams from seeming too thick.
Iron the jeans to allow for clean folding, then turn the jeans inside-out. Fold the future hem up 1/2-inch and pin it in place. Again, at this time it can be helpful to iron. Fold the hem over another 1/2-inch. The hem should still be 1/2-inch in length, but should have three layers of material. Always iron at this point—it will make the material nice and flat for sewing.
When you start sewing, start near a seam and hand-turn the machine over the rise of the seam to make sure you don't break your needle. Once on the seam, proceed around the leg of the jeans, keeping 1/8-inch from the top of the hem. For the best results, be sure to sew from the inside of the jeans. Once you have completed the circuit around both legs of the jeans, just cut away any excess thread and you're done.