T-Shirt Sizing Chart
All shirt Widths measured from under the arms (chest) while laid flat. All Lengths measured from bottom of shirt to the highest point of the shoulder. If you're unsure what size to buy, try measuring a similar shirt that you already own, that fits well, and compare those measurements to the size chart.
These measurements are approximate and are accurate for the majority of the shirts. The exact measurements can and do vary slightly. They may shrink so keep this in mind when selecting your size. To minimize shrinkage, dry on low heat or hang to dry