How To · Fashion · Build
How to Read a Size Chart and Actually Understand Fit Terminology
Size charts aren't one-size-fits-all instructions—they're blueprints. Here's how to read them like a pro and stop the endless return cycle.
5 min read · IrisEvery brand measures differently. A medium at one label might be a large at another. The culprit isn't inconsistency—it's that most men buy by size alone, not by actual measurements. Size charts exist to bridge that gap, but they're useless if you don't know how to use them.
This guide teaches you to measure yourself accurately, decode what brands actually mean by 'slim' or 'regular,' and match your body to the right fit every single time. No more surprises at the door.
Measure yourself once, measure correctly, and you'll never buy a shirt that pulls at the shoulders again.
What you'll need.
- 01Soft measuring tape
- 02A well-fitting reference garment
- 03Shoes you'll wear with the item
- 04Phone or notebook for recording measurements
Step one · 2 minutes
Measure your chest the right way
Strip to your undershirt or go bare-chested. Wrap a soft measuring tape around the fullest part of your chest—usually at nipple level—keeping it parallel to the ground and snug but not tight. Don't pull the tape or let it sag. Write down the number. This is your true chest measurement, and it's the anchor point for most size charts.
Measure in the morning before your body swells from eating or exercise. Consistency matters.
Step two · 2 minutes
Get your shoulder width and sleeve length
For shoulder width: Put on a shirt that fits well in the shoulders. Measure from the edge of one shoulder bone to the edge of the other, straight across the back. For sleeve length: Extend your arm at a 90-degree angle and measure from the center back of your neck, across your shoulder, down to your wrist bone. Both numbers matter for shirts, jackets, and outerwear—ignore them and you'll look like you're wearing your dad's clothes.
If you don't have a well-fitting reference shirt, ask a tailor to measure you. It costs nothing and takes five minutes.
Step three · 1 minute
Measure inseam and rise for pants
Inseam: Wear shoes you'll actually wear with those pants. Measure from your inner thigh (where the seam sits) down to the top of your shoe. Rise: Measure from the top of your hip bone down to your crotch. Most men ignore rise and regret it—too short and you'll look like you're expecting a flood; too long and you'll trip over fabric. Both numbers are non-negotiable.
Inseam should hit right at your shoe without bunching or dragging. If you're between sizes, go shorter—a tailor can't add length, but they can hem.
Step four · 2 minutes
Decode fit terminology on the size chart
Brands use different language: 'slim,' 'regular,' 'relaxed,' 'athletic.' These aren't standardized. Look at the actual measurements, not the label. If a 'slim' fit at Brand A has a 19-inch chest at size M and a 'slim' fit at Brand B has a 20-inch chest at size M, they're different animals. Cross-reference the measurements against your own numbers, not the fit name. The chart is your truth; the descriptor is marketing.
Screenshot or bookmark size charts from brands you buy from regularly. You'll start to see patterns in how they cut.
Step five · 2 minutes
Account for fabric and shrinkage
Cotton shrinks. Linen relaxes. Synthetic blends are more stable. Check the fabric content on the product page and adjust your expectations. If a shirt is 100% cotton and measures exactly your chest size, it'll shrink and feel tight after washing. Add half an inch of breathing room for natural fabrics. For blends, follow the brand's care instructions—some pre-shrink, some don't.
When in doubt, size up slightly in natural fabrics. You can always layer; you can't stretch a shrunken shirt.
Step six · 1 minute
Match your measurements to the chart, not the size number
Find the row on the size chart that matches your measurements most closely. If your chest is 39 inches and the chart shows a medium at 38 inches and a large at 41 inches, the large is your answer—even if you usually wear a medium. Ignore the size label. Your body is the only size that matters. Order that size and move on.
If two measurements pull you in different directions (chest says medium, sleeves say large), prioritize the chest. Sleeves can be tailored; a tight chest cannot.
How to know you've read the chart correctly.
The garment arrives and fits without pulling, gaping, or bunching. Sleeves end at your wrist bone. Chest has about a hand's width of breathing room. Pants don't drag on the ground or show your ankles. You don't need to exchange it. That's success.
Questions at the mirror.
What if I'm between two sizes on the chart?
Size up if you're between sizes. Extra room is easier to tailor than a tight fit. The exception: if you're between sizes in the shoulders or sleeves, size down—those are harder to alter.
Do I need to measure myself every time I order?
No. Measure once and keep your numbers in your phone. Update them annually or if your body changes significantly. When ordering, compare your stored measurements to the brand's chart.
Why does the same size fit differently at different brands?
Different factories, different patterns, different quality control. Brands don't use the same molds. That's why the chart matters more than the label.
Should I size up for layering?
Only if you plan to layer regularly with thick pieces. For normal layering (t-shirt under a shirt), your regular size is fine. If you're buying for winter layering, add about half an inch to chest and sleeves.