Light & ShadeLSLPNT006 Ladies Soft Touch Loungewear Sweatpants Joggers Jog Pants

What are the large size measurements

I'm a size 12 and looking for a loose fit should I get a M or a L?

What size would i need for 16-18 please i have looked through all reviews and opinions seem to differ and their isnt a size guide.

What size is large ? Size 16?