How To · Fashion · Build
Find Your True Shirt Size Without the Guesswork
Most men wear the wrong shirt size because they've never actually measured themselves. We'll walk you through the three measurements that matter, using nothing but a soft tape and a shirt that already fits.
5 min read · IrisThe shirt size printed on a tag is almost meaningless. A medium at one brand might be a small at another. A 15.5 neck from a heritage shirtmaker fits nothing like a 15.5 from fast fashion. What matters is knowing your actual measurements—and how to read a size chart that respects them.
You need three numbers: chest width, shoulder width, and sleeve length. With those, you can order confidently from any brand, anywhere. This takes ten minutes and requires only a soft measuring tape and a shirt you already like wearing.
A shirt that fits your shoulders will always look better than one that's roomy in the chest but tight across the back.
What you'll need.
- 01Soft fabric measuring tape
- 02Well-fitting reference shirt
- 03Notebook or phone notes
Step one · 2 minutes
Gather your tools
Find a soft fabric measuring tape (the kind tailors use, not a rigid ruler). If you don't have one, order a cheap one online or borrow from someone who sews. You'll also need a shirt that fits you well—something you reach for regularly and feel comfortable in. This is your reference garment.
Avoid stretchy or oversized shirts as your reference. Pick something fitted but not tight.
Step two · 2 minutes
Measure your chest
Lay your reference shirt flat on a clean surface. Measure across the chest from armpit to armpit in a straight line, then double that number. This gives you your true chest width. Write it down. Do not pull the tape tight—let it sit naturally where the fabric falls. If your shirt is slightly loose, that's fine; you're measuring the garment, not your body.
Measure at the fullest part of the chest, usually a few inches below the shoulder seam.
Step three · 2 minutes
Measure your shoulders
Measure from shoulder seam to shoulder seam across the back of your reference shirt. This is your shoulder width. Most men overlook this, but it's critical—a shirt with shoulders that sit too far forward or back will never look right, no matter how well the chest fits. Write this number down too.
The shoulder seam is where the sleeve attaches to the body. It should sit right at the edge of your actual shoulder bone.
Step four · 2 minutes
Measure your sleeve length
Measure from the center back neck down to the cuff of your reference shirt. This is your sleeve length. Alternatively, measure from your wrist bone to your shoulder bone on your own arm, then add half an inch for the shirt to sit properly. Both methods work; pick whichever feels more reliable to you.
Sleeves should end at your wrist bone when your arms hang naturally. If they're too long, you'll look sloppy; too short, and you'll look like you're waiting for a growth spurt.
Step five · 1 minute
Cross-reference with brand size charts
Visit the website of any brand you want to buy from and find their size chart. Most reputable brands publish one. Compare your three measurements against their chart. You may be a different size at different brands—that's normal. Bookmark the size charts for brands you like so you can reference them quickly before ordering.
If your measurements fall between two sizes, choose based on fit priority: go up in chest if you prefer comfort; go down if you prefer a sharper silhouette.
Step six · 1 minute
Order and verify
Place your order using the size that matches your measurements on that brand's chart. When it arrives, try it on immediately. If the shoulders feel right but the chest is slightly loose, that's a win—you can always layer or have it tailored slightly. If the shoulders are off, return it and try the next size. Shoulders are non-negotiable; everything else can be adjusted.
Keep your measurements written down in your phone notes. You'll reference them constantly.
How to know it works.
A properly sized shirt should feel comfortable across the shoulders, allow you to move your arms freely, and sit close enough to your body that you can see your silhouette without being restrictive. The sleeve should end at your wrist bone, and the hem should hit at your hip or slightly below.
Questions at the mirror.
What if I'm between two sizes?
Prioritize shoulders first. If your shoulder measurement falls between two sizes, order the size where the shoulders are closest. A slightly roomy chest can be tailored or layered; bad shoulders can't be fixed without expensive alterations.
Do I need to measure my neck for dress shirts?
Yes, but separately. Neck size is independent of chest size. Measure around the base of your neck with the tape snug but not tight, then add half an inch. That's your dress shirt neck size. Most casual shirts don't use neck sizing, so don't worry about it unless you're buying button-ups.
What if my reference shirt doesn't fit perfectly?
Pick a different one. You need a shirt that actually works for you. If nothing in your closet fits well, borrow one from a friend whose build is similar to yours, or try on shirts in a store and note which size felt best, then measure that one.
Should I account for shrinkage?
Only if you're buying 100% cotton and plan to machine wash it hot. Most modern shirts are either pre-shrunk or blended with synthetics. Check the care label. When in doubt, order your true size and follow the care instructions.