Please note that this sizing chart is not an absolute recommendation as best fit is achieved in 3 dimensions. Size charts and even the sliding scale Brannock device found in some stores are only designed to establish a starting point for fit. There is no substitute for an in person fitting.
Standing on a piece of paper, place your heel comfortably against a flat surface and measure the distance to the tip of your toes. Do not use a wall with a baseboard as this will skew the measurement. Have someone trace your feet; measure both feet and use the largest measurement.
Take the measurement in the socks you anticipate wearing with the boots.”