Is there a difference between plus size 1X and misses size XL in women's clothing?

Yes, XL is size 16-18 !X is 18-20. sometimes we need to go up or down depending on the body part. I wear XL on top but !X on bottom. if its a dress and its cut full you can get away with the XL and feel good.

I just read that an XL is a 16 and a 1X is an 18.