UK vs US Men’s Shirt Sizes: What You Really Need to Know

🇺🇸 UK vs US Men’s Shirt Sizes: What You Really Need to Know

1. Collar & Chest Size Equivalence

Both UK and US shirts typically use the same numeric sizing in inches (e.g., 15.5″ collar, 40″ chest). So:

• A US 15.5 in shirt roughly equals a UK 15.5 in shirt.

• A US 40 (chest) equates to UK 40, as the system is largely identical.

But misfit arises due to differing cuts, sleeve lengths, and fit preferences:

• US shirts (like Brooks Brothers, Polo) tend to be roomier—generous in torso, sleeve, shoulder.

• UK shirts (e.g., Reiss, Charles Tyrwhitt) often run slimmer—narrower shoulders, tighter through arms, body.

2. Sleeve Length Labelling

• US brands list sleeve size in ranges (e.g., 34–35 in).

• UK brands may list a single length or use cm.

Always check length versus your actual arm measurement.

3. Alpha-Size (S–M–L) Differences

“Medium” from the UK and US aren’t interchangeable. UK medium is usually slimmer—might feel tighter in chest or sleeves if you’re a US M.

📏 Converting Sizes: A Practical Chart

Note: For slim-fit UK brands, you may need to “size up” if between sizes.

👔 Styling Advice: Choosing Cut & Look

Classic Office Shirt

• Fabric: Crisp poplin

• Collar: Spread or cutaway

• Fit: Slim/tailored for suiting

• Pair With: Tailored trousers & leather dress shoes

  • UK Brands: Reiss, Charles Tyrwhitt

  • US Brands: Brooks Brothers, Banana Republic

Smart Casual

• Fabric: Oxford cloth, brushed cotton, subtle checks/stripes

• Wear: Sleeves rolled, untucked or half-tucked

• Brands: AllSaints (UK), J.Crew (US), Club Monaco

Evening Look

• Colour: Dark navy, charcoal or black

• Detail: Satin buttons or a slight sheen

• Fit: Skinny/dress fit

• Brands: Ted Baker (UK), John Varvatos (US)

✅ Best Brands by Fit and Style

🧠 Tellar.co.uk: Eliminate Sizing Guesswork

Converting between US/UK sizes is only part of the puzzle. Different fits, cut styles, and fabric drape still matter. That’s where Tellar.co.uk helps—using real sizing data for 1,500+ brands to find your ideal fit.

How It Works:

1. Get precise measurements (neck, chest, waist, hips, sleeve)

2. Add them—or your known shirt size—into Tellar

3. Choose brand & fit type (e.g. slim/tailored/traditional)

4. Instantly see which size suits you in US and UK brands

Tellar knows:

• Reiss tends to run slim; suggests sizing up to avoid tight arms or chest 

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• It converts UK sizes like 15.5″ collar directly to their US equivalents—without guesswork

💡 No more ordering multiple sizes or risking returns.

✅ Start here: Create your free Tellar profile