Using our perfectFIT custom sizing tool is the simplest way to determine cuff size. Just a couple of measurements and we will do the rest to ensure a perfect fit! You can also use our crutch sizing chart here - https://smartcrutch-usa.com/selecting-your-smartcrutch-size/ or see the video (currently under construction) on choosing a cuff size below. If you need us to help determine what crutch size you need, please provide us with your height, your forearm circumference at the widest part of the forearm, and your inner forearm length, measured from the crease of your wrist to the fold of your elbow, with your elbow bent at a 90° angle. You can email this to support@smartcrutch-usa.com   How to choose smartCRUTCH cuff size