When buying running socks, sizes are extremely variable. Some “one size fits all” socks come in either women’s 5-10 or women’s 6-11. If you are at the high or low end of the spectrum, size 5 or 11 for example, it can be difficult knowing what size you need. Make sure to review the sizing chart and read at least 3-4 reviews to see what people had to say regarding sizing to help you get the best fit.