What size t-shirt am I? The fastest reliable answer is to lay a tee you already love flat, measure it across the chest and from shoulder to hem, and match those two numbers to the brand's flat-measurement chart rather than trusting the letter on the tag. On our standard adult tee, a shirt that measures 22 inches across and 30 inches long is a Large, 24 by 31 is an XL, and 26 by 32 is a 2XL. If the width fits but the length does not, a Tall size is usually the fix.
That is the whole method in two sentences. The rest of this guide walks through it step by step, explains how to read a chart like ours, and covers the tricky cases: falling between sizes, women's and youth fits, and the moment a Tall beats sizing up.
Why the letter on the tag is not your size
An L from one brand and an L from another can be very different shirts. There is no mandatory clothing size standard in the United States, so manufacturers size their products according to their own preferences. Wikipedia's article on vanity sizing notes that although sizing standards from ASTM exist, most companies no longer use them, and it cites a 2010 investigation that measured men's pants labeled with a 36 inch waist and found actual waists ranging from 37 to 41 inches. Shirts are no different.
So "I'm a Large" is really "I'm a Large in the brands I usually buy." That is a fine starting point, but numbers are better. The good news is that you do not need a tailor or a fancy tape measure routine. You need one shirt that fits the way you like and a ruler or tape measure.
How to measure a t-shirt you already own
Measuring a shirt (rather than your body) is the most accurate way to shop, because a flat-measurement chart describes the shirt, not the person. You are comparing like with like.
Step 1: pick your best fitting tee
Choose a plain, short-sleeve crew neck that fits the way you want your next one to fit. Not the stretched-out gym shirt and not the one that shrank last summer. If your favorite is a little short, measure it anyway and note that you want more length.
Step 2: lay it flat and smooth
Put it face up on a table or a hard floor. Smooth out wrinkles without stretching the fabric. Line up the side seams (or the sides, if the shirt has no seams) so the front and back sit evenly.
Step 3: measure the chest width
Measure straight across the chest, from side to side, about one inch below the armholes. That number is the flat width. Do not double it. Charts like ours list the flat width, and doubling happens only when you want the full circumference (a 22 inch flat width is roughly a 44 inch chest all the way around the shirt).
Step 4: measure the body length
Measure from the highest point of the shoulder, right where it meets the collar, straight down to the bottom of the hem. That is the body length. Keep the tape vertical; angling it toward the center inflates the number.
Step 5: write both numbers down
Width by length, in that order, like "24 x 31." That pair is your real t-shirt size, and it travels with you from brand to brand.
How to read a flat-measurement chart
Here is our standard adult tee, measured flat, width by length in inches. Every chart like this carries a tolerance; ours is plus or minus one inch, which is normal for knit garments.
- S: 18 x 28
- M: 20 x 29
- L: 22 x 30
- XL: 24 x 31
- 2XL: 26 x 32
- 3XL: 28 x 33
- 4XL: 30 x 34
- 5XL: 32 x 35
- 6XL: 34 x 36
- 7XL: 36 x 37
Notice the pattern. Each step up adds two inches of flat width (four inches all the way around you) but only one inch of length. That single fact explains most fit frustrations. People size up to get length and end up with a shirt that is roomy everywhere except where they wanted it.
Match width first
Width decides comfort. Find the size whose width is closest to your favorite shirt's width. If your tee measures 24 inches across, start at XL.
Then check length
Now compare the length. If your tee is 31 inches long and you like it, XL is your size. If your tee is 31 inches and you wish it were longer, keep reading, because the answer probably is not 2XL.
What if you are between sizes?
Real shirts rarely land exactly on a chart line. Here is how to decide.
- Between widths, like the fit relaxed: go up. An extra inch of flat width reads as easy and comfortable on most people.
- Between widths, like the fit trim: go down, especially on 100% cotton, which tends to relax and soften with wear.
- Plan for the first wash: our adult tees are 100% ring-spun cotton, preshrunk jersey knit. Preshrunk means much less shrinkage, not zero, and what does happen shows up mostly in the length. If you are already on the edge of too short, do not go shorter.
- Use the tolerance: with plus or minus one inch built in, a half inch difference from your favorite shirt is noise. Two inches is a real difference.
When a Tall fits better than sizing up
If you are long in the torso, the regular chart will fight you. Sizing up from XL to 2XL buys one inch of length and two inches of width you may not want. A Tall does the opposite: it adds three inches of body length at the same width as the regular size.
- XL Tall: 24 x 34
- 2XL Tall: 26 x 35
- 3XL Tall: 28 x 36
Look at what that means in practice. An XL Tall is as long as a regular 4XL (34 inches) while keeping the XL's 24 inch width. A 2XL Tall is as long as a regular 5XL. If your measured shirt says "my width is fine, my length is not," a Tall is the shirt that was made for you. Our Tall t-shirts category collects them in one place.
Bigger sizes: 2XL, 3XL and beyond
The measuring method is exactly the same for plus sizes, and it matters even more, because the gap between brands grows as sizes go up. Measure your best fitting shirt, match the width, then check the length.
If you land at 26 inches across, start in our 2XL category. At 28 inches, our 3XL category is your shelf. For 4XL and up, our Plus Sizes category gathers every design available in larger sizes. One honest note: size runs vary by design and by shirt color, so a design might reach 5XL in black and stop earlier in another color. Always check the size selector on the specific shirt.
Women's sizing notes
Most graphic tees, ours included, are unisex, which in practice means cut on a traditional men's pattern: straighter through the body, wider in the shoulders, and longer in the sleeve than a women's cut.
- Measure a unisex tee you own if you have one, since that is the cleanest comparison.
- If you only own women's cut tees, expect them to measure narrower and often shorter. Many women go down one size in unisex for a closer fit, or stay in their usual size for a relaxed, boyfriend style drape. Either is right; it depends on the look you want.
- Women's cut shirts have their own charts. Where a design comes in a women's body, check that listing's chart rather than borrowing the unisex numbers.
Youth sizing notes
Kids' clothing is often labeled by age, and age is a rough guide at best. Two eight year olds can be four inches apart in height. The same measuring trick works here too: lay a shirt that fits your kid flat, measure width and length, and compare to the youth chart on the listing you are looking at.
- Buying ahead? One size up usually buys a season of growth, and kids rarely mind a slightly long tee.
- Teen in between? An adult Small (18 x 28 on our chart) is often the bridge out of youth sizes. Measure before you decide.
Measuring your body when you have no shirt to copy
If you do not have a tee that fits the way you want, measure your chest instead. Wrap a soft tape around the fullest part of your chest, under the armpits, keeping it level and snug but not tight. Divide that number by two to get your body's flat width. Then add ease, which is the extra room that makes a shirt comfortable.
- Close fit: add about 1 to 2 inches to your flat body width.
- Classic fit: add about 2 to 3 inches.
- Relaxed fit: add about 4 inches or more.
For example, a 44 inch chest is 22 inches flat. Add 2 inches of ease and you are looking at a 24 inch shirt, which is an XL on our chart. This is a starting point, not a verdict, which is why measuring a real shirt is still the better method.
A quick checklist
- Measure a tee you love: flat width one inch below the armholes, length from the high shoulder to the hem.
- Match width to the chart first, then check length.
- Between sizes? Go up for relaxed, down for trim, and never go shorter on length.
- Width right but too short? Choose a Tall instead of sizing up.
- Check the size selector on each design, because size runs follow shirt color.
For every chart and size range in one place, see our plus size nerd t-shirts guide.
The shirt that fits is the shirt that gets worn
So, what size t-shirt are you? You are two numbers, width and length, and now you know how to find them. It is worth the five minutes. A shirt that fits right is the one you reach for on a Saturday, the one you wear to the convention, the one somebody across the room recognizes before they recognize you. Get the fit right, and the shirt can do what a great fan tee does best: start the conversation.