Our age recommendation is 99% accurate. For comparison, we've created an approximate standard size chart (corresponding to the Coop brand Naturaline). If you're still unsure about the size, just write to us; we're happy to advise you. Ideally, you should provide us with your child's waist measurement and leg length. We'd be happy to send you the measurements and more photos of the trousers via Instagram. You're also welcome to come and see and try on the trousers in Interlaken.