If you don’t own a pair of shorts, put the sweatpants on, make a mark with a chalk or pen where you want them to end, then take them off.
If you want to hem the cuffs later for a finished look, add 1⁄2 inch (1. 3 cm) to the cuffs. If you don’t have a pair of shorts, use a ruler to draw a straight line across 1 of the legs. Angle the line up towards the inseam slightly. [4] X Research source
If you don’t have a pair of shorts, cut off the leg that you marked. Fold the pants in half, then use the cut edge as guide for cutting the second leg off.
It might be a good idea to place a drop of super glue or fabric glue on the cut edges of the seams. This will prevent the seams from splitting.
Be sure to backstitch when you start and finish sewing, and to snip the excess thread off. If you don’t know how to sew, you can use fabric glue or iron-on hem tape instead. Follow the instructions on the label or packaging of your chosen product.
If you can’t find sweatpant fabric, use T-shirt or jersey fabric instead.
Double the width of the elastic that you’ll be using for your waistband. This is how far the shorts should be from the top edge of the fabric. Place the shorts in such a way so that you have enough room to cut a second pair.
You are adding extra length to the top edge for the waistband. You can trace the shorts first. Use a tailor’s chalk for dark fabrics, and a tailor’s pen for light fabrics. If you don’t want to hem the cuffs, do not add a 1⁄2 in (1. 3 cm) seam allowance to the bottom of the shorts.
Use sewing pins to hold the fabric together as you sew, if needed. Remember to take them out when you are done sewing.
Make sure that you are folding the cuff on the outside of the pant leg. The raw edge will eventually be on the inside.
At this point, you can trim the side seams down to 1⁄4 inch (0. 64 cm), or you can leave them as they are.
Secure the curved part of the crotch and seat with sewing pins, if you have to, but remember to remove them later.
You will need to pull on the elastic as you sew so that it stretches to fit the waistband. Remember to take the pins out when you are done!
Turn the shorts right-side-out when you are done. They are now ready to wear! It would be a good idea to quickly go over them, and trim off any loose or hanging threads, however.
