Measuring for size is important. This will allow wiggle room at the toe but a firm grip on the sides of the feet. Please use the below as a guide focusing on the foot length. All boots are narrow width to fit a woman's foot.
The length of your foot should be shorter than the boots Foot Length Maximum. This is so your toes don't hit the end of the boot for maximum comfort so be sure to measure a fully flat foot.
The width of your foot should be equal to or wider than the boots Foot Width Minimum. This is so you don't slip from side to side in the boot for maximum comfort.