Grab a measuring tape if you have one handy, or a string if you don't, and wrap it around your wrist. Depending on the measurement, your size is as follows:

  • Extra Small: 14.7cm / 5.8in (typically the size for children and very petite women)
  • Small: 15.7cm / 6.2in (typically the size for women and thinner men)
  • Medium: 17.2cm / 6.6in (most common size for men)
  • Large: 18.5cm / 7.3in (slightly less common size for men)
  • Extra Large: 19.8cm / 7.8in 

*If you don't have a measuring tape or ruler handy, you can always use a dollar bill to approximate. Every US dollar bill (regardless of whether it's $1, $5, $10, etc.) is 6.14 inches long. Wrap one around your wrist. If there's overlap, you're an extra small; If the dollar closes end-to-end neatly, you're a small; If you're still seeing just a smidge of your wrist between the edges of the bill (say a pinky's width or less), you're a medium; If you're seeing more like a thumb's width of your wrist, you're a large; and if it's more than that, you're an extra large.