[gmku]

To find your true foot size, stand with one foot on a piece of paper and then bend over and trace with a pen or pencil around your foot. Measure from heel to toe, and this is your size. For example, 11 inches is a size 11.

Then pay attention to what consumer reviews say about how a shoe fits. If most reviews say it fits larger than its stated size, you'll know to size down from your foot size. If they say it runs true to size, simply buy your size.