Size 18 jeans but size 24 smart trousers

Hi all,

I’m so puzzled 😔 and this has got me a little down not going to lie,

I wear a UK size 18 jeans, But I do only wear like stretch straight leg or “skinny’s”

I’m starting a new job which requires smart navy trousers. And in my horror had to get a size 24! Because my hips and bum are quite clearly wayyy to big.

Does anyone else have this jump in sizing?

Thanks all xx