Sizes will differ from product to product. Even our tee-shirts vary in sizes (just a little) depending on the cut, the loose fit, ... etc
So please consult the size chart associated with each item.
This size chart is just to give you an idea of the average size of one of our typical t-shirts.
Take an item you currently own and which fits you weil. Pleace it on a flat surface. Measure the distances A and B .... and then select the size that matches best. Better to choose a size slightly larger than too small :)