Since all of Redback’s boots are unisex, we use a standardised UK sizing system with one range of numbers. If you know your US women’s or EU size, our conversion chart can help to match this with our system, but the safest bet will be to take your actual measurement in mm since the chart covers this comprehensively.
Beyond length, consider the width across the ball of your foot and the room over your instep, and, if possible, try the boots on with the socks you wear at work. Due to design differences, sizes available vary by model, so check each product page before you buy.