Try on the jeans and mark the desired hem length with chalk or a fabric marker
Turn the jeans inside out
Measure the marked length from the original hem to confirm accuracy
Fold the excess fabric up to the mark
Pin the fold evenly around the leg, keeping the seam lines aligned
If you want to keep the original hem shape, press the fold with an iron
Measure the cuff width you want (optional) and ensure both legs match
Remove the jeans and trim excess fabric outside the pinned fold, leaving about 1 to 1.5 in (2.5 to 3.8 cm) for a seam allowance
Fold and press the new hem allowance up, then fold again to the final hem width
Pin the final fold in place
Sew the hem using a sewing machine or hand stitching
Use a denim needle (or heavy-duty needle) and matching thread
Sew straight along the folded edge, removing pins as you go
Backstitch at the start and end to secure stitches
Press the finished hem with an iron to set the seam
Repeat for the other leg
Try on again and adjust if needed
Clean up loose threads and remove any markings