Polo Ralph Lauren vs Port Authority: which size fits the same?
In polos, a Polo Ralph Lauren L is closest to a Port Authority M (1″ snugger).
Polos
Port Authority polos measure about 1½″ more around than Polo Ralph Lauren at the same size. A Polo Ralph Lauren L is closest to a Port Authority M (1″ snugger).
| Polo Ralph Lauren | Chest · length | Closest Port Authority | Chest · length | Port Authority is |
|---|---|---|---|---|
| Polo Ralph Lauren XS | 34¼″ · 24½″ | none close | ||
| Polo Ralph Lauren S | 37¼″ · 25¼″ | Port Authority XS | 36½″ · 27½″ | ¾″ snugger |
| Polo Ralph Lauren M | 40¼″ · 26″ | Port Authority S | 39½″ · 28½″ | ¾″ snugger |
| Polo Ralph Lauren L | 43½″ · 27″ | Port Authority M | 42½″ · 29½″ | 1″ snugger |
| Polo Ralph Lauren XL | 47½″ · 28¼″ | Port Authority XL | 48½″ · 31¼″ | 1″ roomier |
| Polo Ralph Lauren XXL | 51½″ · 29¾″ | Port Authority XXL | 51½″ · 32¼″ | the same around |
From Polo Ralph Lauren: Polo Ralph Lauren Custom Slim Fit Mesh Polo. From Port Authority: Port Authority Silk Touch Polo (K500), Port Authority Dry Zone UV Micro-Mesh Polo (K110), Port Authority Core Classic Pique Polo (K100). Relaxed and oversized cuts are left out.
More: Polo Ralph Lauren sizing · Port Authority sizing
Get your exact size in any of these
Add three shirts you own that fit well. FitCard compares their real measurements with every shirt here and tells you the one size to buy, and why, in terms of your own shirts. Free, no tape measure.
Garment measurements: the shirt itself, chest all the way around and length from shoulder to hem, from each brand's own chart or wholesale spec sheet, checked November 2026. Shirts with half or more cotton are shown as they come out of a dryer (about 2% less around and 4% shorter). Brands change their cuts, so check the shop's chart before you buy.