Casual fit tee. Washed cotton fabric has some stretch. Stay in your normal size for intended fit. If between sizes, size down for a more fitted look or up for more oversized boyfriend fit.
Melissa is 5'5 between an Extra Small (XS) and Small (S). and wears a size Small.
Model is 5'7 wearing an Extra Small (XS).
All measurements are standard design measurements of the garment laying flat. Double the number for circumference. This does not include any stretch the garment might have.