To help you decide which size is best to buy, all our products have size guide charts on their product page. Simply click the ‘Size Guide’ tab in the product description area. If you would like a little more help and guidance on how to measure your child please visit https://www.davidluke.com/for-parents/how-to-measure-your-child-school-uniform where we have helpful guides which explain how to measure your child for school uniform. You can also watch our easy to follow ‘How to Measure’ video, showing you the correct and accurate way to measure your child for their school uniform. Please note: Taking actual body measurements are more of an accurate guide than using age.