Wrap the measuring tape around your wrist just above the wrist bone with your palm open and facing up.

Note down the measurement of your wrist ( in cm)

Wrap the string around your wrist just above the wrist bone with your palm open and facing up.

Mark where the ends meet with a pen or marker.

Lay the string flat and measure it to where you've made your mark and note down the measurement to find your wrist size ( in cm)