You’re browsing for a high-end Nike Elite or a Mitchell & Ness throwback, and instead of the usual "Small" or "Extra Large," you see a list of numbers: 40, 44, 48, 52. If you feel confused, you aren’t alone.

Numerical sizing is the industry standard for authentic nfl jerseys. Unlike the "Game" or "Limited" versions that use letter sizing, these numbers are based on actual chest measurements and provide a more precise, athletic fit. Here is your cheat sheet to mastering numerical sizing.

What Do the Numbers Actually Mean?

In theory, the number represents the chest circumference of the jersey in inches. For example, a size 48 is designed for someone with approximately a 48-inch chest measurement (including breathing room). However, because these are athletic garments, the "fit" depends on the brand and the template.

The Conversion Chart: Numbers vs. Letters
While every brand is slightly different, here is the general industry standard for converting numerical sizes to the S-M-L-XL system we all know:

Size 40: Equivalent to Small (S)Size 44: Equivalent to Medium (M)Size 48: Equivalent to Large (L)Size 52: Equivalent to Extra Large (XL)Size 56: Equivalent to 2XLSize 60: Equivalent to 3XL

The "Athletic Cut" Warning
Even if you usually wear a Large T-shirt, an nfl jersey size 48 might feel different than you expect.

Nike Elite: These are cut for athletes. They are narrower in the waist and tighter in the sleeves. If you have a larger midsection, many fans recommend sizing up one numerical level (e.g., move from 48 to 52).Mitchell & Ness: These retro jerseys are often longer and have a more "boxy" vintage feel. A size 48 here might feel truer to a traditional Large than a modern Nike Elite does.

How to Choose Between Size 48 and 52?
This is the most common dilemma for fans.

Choose Size 48 if: You are about 5'10" to 6'1" with a lean or athletic build and want to wear the jersey over a T-shirt.Choose Size 52 if: You prefer a relaxed fit, you are over 200 lbs, or you plan to wear your jersey over a heavy hoodie for cold-weather games.

Why Use Numerical Sizing?

The reason the Pros use numbers is precision. When an NFL player is on the field, they can't have excess fabric being grabbed by defenders. Numerical sizing allowed Nike to create 10+ different size options (including "Plus" lengths) to ensure every player has a custom-feeling fit. As a fan, buying a numerical size gives you that same "on-field" feeling and premium quality.

Final Thoughts

Don't let the numbers intimidate you. Once you know that size 48 is your "Large" and size 52 is your "XL," shopping for premium authentic nfl jerseys becomes much easier.