How to Choose the Right Dress Shirt Size: A Complete Guide to Italian Luxury Brands

Choosing the right dress shirt size is more complex than it looks. Unlike a blazer — where the shoulders are the primary reference point — a dress shirt depends on at least four measurements working together. If you've already read our guide to blazer sizing [INTERNAL LINK: /blogs/style-guide/suit-blazer-size-guide-italian-brands], you know how much precision matters when buying tailored clothing online. With dress shirts, the margin for error is even smaller.

In this article:

• How to measure your collar correctly
• The other measurements that matter
• How to measure yourself at home
• Brand-by-brand fit guide: Truzzi, Finamore 1925, Barba, Borriello, Mazzarelli
• Slim fit vs regular fit: which to choose
  
• The most common mistakes when buying online
• FAQ

Why Dress Shirt Sizing Is More Complex Than a Blazer

A blazer is chosen primarily by shoulder width. A dress shirt is not. Collar, shoulders, chest and sleeve length all need to be correct: one measurement off throws everything else. A collar that's too tight is unwearable within minutes. A chest that's too wide creates excess fabric that can't be fixed. For anyone buying online without the option to try on, a precise fit guide is the closest thing to having a tailor beside you.

The Measurements That Actually Matter

The Collar: the Most Important Measurement

Italian dress shirt sizes correspond directly to the collar circumference in centimetres. If your neck measures 42.5 cm, order size 43. The rule is simple: always round up. A shirt that's tight at the collar is uncomfortable and visible. A shirt with one extra centimetre of room at the collar is perfect.

How to measure: wrap a flexible tape measure around your neck, horizontally, just below the Adam's apple. Keep it snug but not tight: you should be able to slip one finger between the tape and your neck. That number is your size.

Shoulders

The shoulder seam should fall exactly at the edge of the shoulder joint, not down the arm, not on the muscle. For the brands we carry (Truzzi, Finamore 1925, Barba, Borriello, Mazzarelli) when the collar is correct, the shoulders generally fall correctly too. The fits are calibrated consistently within each brand.

Chest

An elegant dress shirt is worn tucked in. The chest should have enough room to move without the fabric pulling or creating horizontal creases. Standard ease for a regular-fit shirt is approximately 10–12 cm over the chest circumference.

Sleeves

The shirt sleeve should extend 1–1.5 cm beyond the jacket cuff. Sleeve length depends on your arm span. For the brands we carry, sleeve length is standard: you won't find unusually short or long cuts relative to the stated size.

How to Measure Yourself at Home

What You Need

• A flexible tailor's tape measure (not a rigid one)

• Paper to note your measurements

• Ideally a second person: some measurements are more accurate when taken by someone else

Step by Step

• Collar: tape around the neck below the Adam's apple. Add 1 cm of ease

• Chest: tape under the armpits at the fullest point of the chest, arms relaxed at sides

• Shoulders: from shoulder seam to shoulder seam across the back

• Sleeve: from the shoulder seam to the wrist, arm slightly bent

• Write everything down and compare with the size chart below

Men's Dress Shirt Size Chart — Conversions

Note: sizes correspond to collar circumference in centimetres. For half-sizes (e.g. 41.5 cm), always order the size above (42).

Brand-by-Brand Fit Guide

This is where the real information is. Sizes are standardised. Fits are not. What follows is based on our direct experience selling these brands, not generic data.

Truzzi: Fit and Advice

Truzzi runs true to size with a regular fit. The collar matches the stated measurement precisely. The shoulder falls correctly and the chest provides a clean, classic ease, neither excessive nor restrictive. It's a shirt built for those who want a polished silhouette without sacrificing comfort. Worn tucked in.

Advice: order your exact collar measurement. No adjustment needed.

Finamore 1925: Fit and Advice

Finamore 1925 runs regular with a precisely crafted construction. The collar is true to size. This is a shirt with a serious artisanal heritage — the fit reflects Neapolitan tailoring tradition: a clean line, defined shoulder, no excess anywhere. Worn tucked in.

Advice: order your exact collar measurement.

Barba: Fit and Advice

Barba requires the most attention when ordering. There are two distinct lines with different fits, identifiable by label:

• White label: regular fit. Order your exact collar measurement.

• Black label: slim fit. If you have a lean build, order your exact size. If you are broader or prefer more room, consider sizing up.

This is a detail that is rarely communicated clearly online. Now you know.

Borriello: Fit and Advice

Borriello runs true to size with a regular fit. Collar accurate, shoulders correct, classic chest ease. This is a shirt that delivers exactly what it promises, reliable for both work and formal occasions. Worn tucked in.

Advice: order your exact collar measurement.

Mazzarelli: Fit and Advice

Mazzarelli has a specific characteristic worth knowing before you order:

• Up to size 41: regular fit leaning slim. Well suited to lean builds or anyone who prefers a cleaner, closer line.

• From size 42 onwards: shaped fit, more structured and relaxed. Better suited to broader builds or those who prefer more comfort and ease.

If you are on the boundary between 41 and 42, the shift in fit is a meaningful factor in your decision. 

 

Brand Fit Summary

Slim Fit, Regular Fit or Shaped Fit: Which to Choose

• Regular fit: suits most builds. Enough room to move without excess fabric. The safe choice for work and formal occasions.

• Slim fit: suited to lean builds. A closer, more contemporary line. On broader builds, the fabric pulls and the shirt loses its elegance.

• Shaped / custom fit: the solution when standard sizes don't work for your proportions. Not available in the brands we carry, but worth considering if nothing fits well off the rack.

The Most Common Mistakes When Buying a Dress Shirt Online

• Using your T-shirt size as a reference. Shirt sizing doesn't work that way: always use your collar measurement in centimetres.

• Not checking the Barba label. White or black: they are two different fits.

• Rounding your collar measurement down. Always round up.

• Choosing based on aesthetics alone and ignoring fit. A slim fit on a broad build is a visible mistake.

• Measuring with a rigid tape measure. A builder's tape measure won't give you accurate body measurements.

Frequently Asked Questions

How do I find my dress shirt size?

Italian dress shirt sizes correspond to collar circumference in centimetres. Measure your neck with a flexible tape measure just below the Adam's apple, keep it snug but not tight, and round up to the nearest whole number. That is your size.

How should a well-fitted dress shirt look?

The shoulder seam should sit exactly at the edge of the shoulder joint. The collar should allow one finger between it and your neck. The chest should not pull. The shirt is worn tucked in, and the sleeve should extend 1–1.5 cm beyond the jacket cuff.

What is the difference between Barba white label and black label?

Barba white label shirts have a regular fit. Black label shirts have a slim fit with a closer cut through the chest. If ordering black label and you prefer more room, consider sizing up from your measured collar size.

Why do Mazzarelli shirts fit differently from size 42 onwards?

Mazzarelli uses a regular-leaning-slim fit up to size 41. From size 42 onwards, the construction shifts to a shaped fit — more structured with more ease. If you are between 41 and 42, factor in this change when deciding.

Can I use the same size across all brands?

For Truzzi, Finamore 1925 and Borriello — yes, your collar measurement translates directly. Pay attention to Barba (black label = slim) and Mazzarelli (fit changes from size 42 onwards).