Believe it or not the bangle in both of these pictures is exactly the same bangle.
This is the perfect example of why it is important to measure the hand size rather than a wrist size when choosing a solid bangle.
It is not enough to measure the circumference of a wrist as some people can have tiny wrists but larger hands.
Bangles usually need to fit over the hand to be worn. Of course, there are Opening Bangles that will open and close around the wrist without going over the hand, but this post looks at solid bangles that don't open.
If you can't visit a jeweller to be measured, the easiest way to work out a bangle size is to measure the inside diameter of a bangle that already fits. As long as it is round and approximately the same width as the bangle you are considering this is a great way to work out a size. Just make sure the bangle isn't flexible, ie if the wearer can squeeze the bangle into an oval shape to get it on it won't give an accurate size for a solid bangle that isn't flexible.
You can also work out a bangle size by measuring the first three knuckles of a fist. There is more information about this method on our Bangle Size page.