i always try to figure out what I will be wearing with a jacket before I buy it. Always try it on. If you will just be wearing t-shirt, then probably don’t need a side up. but if you think at some point you will have a shirt and sweater go size up. I like my jackets bigger for some reason anyways so I always get a larger size. But I will recommend you to Email: [email protected] There’s no one-size-fits-all fashion advice. For example, a woman who is only wearing a thin blouse may find that the Credit Island Trash Pandas With Tanks Shirt but in fact I love this jacket or coat she wants to wear over it is too tight. However, if a woman has a winter coat that fits her reasonably well but she wants to wear over another item, she’ll want to size up in order to be able to fit in all the layers.