Premium Performance Polo Size Guide | Where We Play Apparel
Here's the size guide content for the Paragon Men's Brunswick Performance Polo - Style 156:
Title: Size Guide – Men's Brunswick Performance Polo
Page content:
All Where We Play Apparel men's Brunswick polos are printed on the Paragon Men's Brunswick Performance Polo (Style 156) — 100% polyester with moisture-wicking and snag-resistant fabric, athletic fit. Runs true to size. If between sizes, size up for a more comfortable fit.

Measurements refer to body size, not garment dimensions.
How to measure yourself: Wrap a tape measure around the fullest part of your chest, keeping it level, to find your chest measurement.