What size?

For the first time I am planning on making a garment for myself that isn’t socks or a blanket but I am not sure how to determine the correct size. I am going to be making the Kertzer Weekend Jacket SRK 180.


For sizing it just gives finished measurements for bust (closed) in inches.

S. M. L. XL. XXL
37. 41. 45. 47. 53

How do I determine which one? :?? Do I go by my undergarment size or the measurement I get when measuring across my bust?:shrug:

Please help me. I am used to making sweaters for babies & children where they give sizes by age or actual kids clothing sizes.

This looks like a pretty loose fitting jacket. I find that the best thing is to take a similar sweater or jacket that I like and measure across the width at the underarms (x2 for both the front and back). Otherwise, measure yourself across the bust and add 3-4" depending on how loose you want the jacket.