Hi there,
Thanks for your question!
For the Youth Large shorts, the waist measures approximately 35 cm and the length is about 44.5 cm. We find that measuring the actual garment is a more accurate way to determine fit than using age or weight, as sizing can vary quite a bit between individuals.
Let me know if you'd like help comparing this to a pair your child already owns!
Best regards,
GB Wear Customer Service Team