You should measure across the chest below armhole when laid flat.
You should start from the shoulder and measure down to the sleeve.
You should measure from the highest point of the shoulder down to product bottom hem.
You should measure from one side to another when laid flat.
Put your height and weight, let us suggest the best size for you.
Please note that when there’s anything wrong with the item you buy, you can change or return it in 1 year, for free without any excuses.