In the obscure world of children's sizing, we know sometimes your stocky toddler wears 5-6 and your skinny 6-year old (that only eats yoghurt) wears 3-4! 

 

To be safe, in the hopes you have a tape measure lying around in a craft cupboard somewhere, here are some measurement guidelines to help you choose your sizing correctly. 

 

If their measurements fall towards the very top end of the size range, consider buying the next one up for longevity, unless they prefer a snug fit.