About 45CM of trousers is enough.
By the way, I run a children's wear Taobao shop, and now I mainly buy clothes for babies aged 2-6 (most children's summer clothes are cleared at a loss, and winter clothes are newly produced at the end of the year). It's a good deal now! Interested to have a look!
Store name
Wailaixifu children's wear store
Go to Taobao to find it. I hope a small advertisement won't disturb your good mood!