What Size Is 1X? Plus Sizes vs XL, With Real Brand Charts
What size 1X is in numbers, how it compares with XL and 2X, and why it changes by brand, with Nike and Dia & Co size charts in inches and how to measure.
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1X is the first plus letter size, the step above XL. Dia & Co lists 1X as US 14/16 with a 44 to 45.5 inch bust, while Nike lists 1X for a 45 to 49 inch bust. It is not the same as XL: plus sizes follow a different figure type, so check the inches on each chart.
This question comes up every time you shop for a patriotic tee or dress in extended sizes, because listings rarely say what their 1X means. Here are the numbers from two brands that publish theirs, and how to use them. The sizing hub covers the bigger picture.
What does 1X measure in inches?
Two published charts, both as body measurements in inches:
| Size | Dia & Co US size | Dia & Co bust | Dia & Co hip | Nike bust | Nike hip |
|---|---|---|---|---|---|
| 0X | 10/12 | 42 to 43.5 | 44 to 45.5 | not listed | not listed |
| 1X | 14/16 | 44 to 45.5 | 46 to 47.5 | 45 to 49 | 46 to 50 |
| 2X | 18/20 | 47 to 49 | 49 to 51 | 49 to 53 | 50 to 54 |
| 3X | 22/24 | 51.5 to 54 | 53.5 to 56 | 53 to 57 | 54 to 58 |
| 4X | 26/28 | 56.5 to 59 | 58.5 to 61 | not listed | not listed |
| 5X | 30/32 | 61.5 to 64 | 63.5 to 66 | not listed | not listed |
Look at a 46 inch bust. It is a 1X at Nike and a 2X at Dia & Co. Neither chart is wrong; each brand sets its own. That is the whole reason to measure.
How is 1X different from XL?
XL belongs to the misses size range, the regular sizes that run from 00 to 20. 1X belongs to the plus range. ASTM publishes separate body measurement tables for each figure type, misses from 00 to 20 and plus women’s from 14W to 40W, and designers use them as a starting point for patterns. The plus tables reflect different proportions, not just a bigger version of the misses ones.
Depending on the brand, a 1X may have more room through the bust, hips and upper arms than an XL, and sometimes a different sleeve and armhole. If XL feels tight in the arms or hips but fine elsewhere, 1X may be the better fit. If XL fits well, a 1X in the same brand may feel loose.
Plus-size 4th of July tops in 1X, 2X and 3X
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How do you measure for a 1X?
Three measurements
Bust: around the fullest part, tape level under the arms. Waist: around your natural waist, the narrowest part. Hip: around the fullest part of your hips and seat. Keep the tape snug, not tight, and stand relaxed.
Compare all three with the chart. If they land in different sizes, think about the garment: a tee is about the bust, a skirt about the waist and hip, a dress about all three. Wrap and stretch pieces forgive a split; fitted woven pieces do not.
What if the listing gives garment measurements?
Many marketplace listings, graphic tees especially, give the shirt measured flat rather than body measurements. Then measure a top you own that fits well: across the chest from armpit to armpit, doubled, and from the shoulder to the hem. Match those numbers to the listing instead of your body.
What comes after 1X?
Letter sizes step up from there: 2X, 3X and 4X are common, and some brands make 5X and 6X. On Dia & Co’s chart each step adds 2 to 5 inches at the bust. If you shop numeric W sizes, ASTM’s plus tables go up to 40W.
Where next?
Ready to shop? The plus-size patriotic tops page compares tees, tanks and tunics, and the dresses page explains which cuts forgive a size split. If you are sizing a man, see what XLT means.
Frequently asked questions
Is 1X the same as XL?
No. XL is a misses size, from the regular size range, and 1X is the first plus size. ASTM keeps separate body measurement tables for the misses figure type (00 to 20) and the plus women's figure type (14W to 40W), so the two are drafted from different proportions.
Is 1X bigger than XL?
Usually, yes. 1X is the next step up from XL; Dia & Co, for example, starts 1X at US 14. Check the inches on the chart, because the overlap between one brand's XL and another's 1X can be large.
What size is 18W?
On Dia & Co's chart, US 18 falls in 2X (18/20). Brands that print W sizes do not all pair them with the same letter, so read the bust and hip measurements on the chart rather than the label.
What is 0X?
Some brands add 0X below 1X for the step between straight and plus sizes. Dia & Co lists 0X as US 10/12 with a 42 to 43.5 inch bust.
Sources
Part of Plus Size and Big and Tall Sizes Explained: Charts and How to Measure.
