XS, 1X or 6XL? How Five Activewear Brands Label the Same Body
Disclosure: Bubblelime (bubblelime.com) is a leggings brand connected to this site's publisher. Treat mentions of it on this page as promotional. How we make this.
- Five activewear brands use five different label systems, and three of them switch notation partway up the run.
- Girlfriend Collective offers the widest ladder we track — XXS, XS, S, M, L, XL, XXL, XXXL, 4XL, 5XL, 6XL — and skips "3XL" entirely.
- Size range and length range do not trade off the way we first wrote: Girlfriend Collective runs the deepest size ladder we track and still sells two or three inseams on most of its leggings.
The gist — An XL is not an XL. PopFlex runs XXS through XL and then switches to 1X, 2X, 3X. Girlfriend Collective uses XXXL where most brands would write 3XL. Baleaf adds numeric waist sizes on some pants. Read the ladder before you read your usual letter.
Correction, Sept. 18: an earlier version said Girlfriend Collective offered no length choice, and drew a trade-off between size range and length range from it. Both were wrong. The Length dropdown appears only on the product page, not the collection page we counted from. Re-counted Sept. 18.
Three letters look like a standard. They are closer to a dialect, and every store speaks its own.
How does each brand label its sizes?
We pulled the size options from every listing in five public catalogs on Sept. 8 and wrote down the ladder each brand uses.
| Brand | Ladder as printed | Steps | Notable |
|---|---|---|---|
| Girlfriend Collective | XXS, XS, S, M, L, XL, XXL, XXXL, 4XL, 5XL, 6XL | 11 | Uses XXXL, then switches to numerals at 4XL |
| PopFlex | XXS, XS, S, M, L, XL, 1X, 2X, 3X | 9 | Switches from X-letters to X-numbers above XL |
| Baleaf | XS, S, M, L, XL, 2XL, 3XL (5XL on a few) | 7–9 | Numeric waist sizes 27–40 on some outdoor pants |
| Senita Athletics | XXS, XS, S, M, L, XL, XXL | 7 | Consistent throughout, no numeral switch |
| Bubblelime | XS, S, M, L, XL, XXL (2XL–4XL on a handful) | 6–9 | Mixes XXL and 2XL notation across listings |
Two traps hide in that table. PopFlex's "1X" sits above XL, so a shopper who wears XXL elsewhere is looking for a label that does not exist on the page. And Bubblelime writes the same size two ways depending on the listing, so a search for "2XL" misses most of its XXL stock.
Why do brands switch notation partway up?
The X-letter system runs out of usefulness. Once you pass XXL, writing XXXXL is unreadable, so brands either move to numerals (4XL) or to the plus-size convention (1X, 2X, 3X), which comes from a different retail tradition where 1X sits around a 14–16.
That history is why 1X and XXL are not interchangeable even when the body measurements overlap. The plus-size ladder is usually cut with different proportions, not just more fabric.
Which brands actually stock the big sizes?
Publishing a ladder is not the same as filling it. Here is how many in-stock leggings at each brand carried a size XXL or larger on the day we counted.
| Brand | In-stock leggings | With XXL or larger | Share |
|---|---|---|---|
| Baleaf | 83 | 78 | 94% |
| Girlfriend Collective | 33 | 28 | 85% |
| Senita Athletics | 121 | 92 | 76% |
| PopFlex | 75 | 57 | 76% |
| Bubblelime | 401 | 66 | 16% |
Depth and breadth pull against each other. Bubblelime carries five times as many legging listings as anyone else here and the narrowest coverage above XL; Girlfriend carries the fewest listings and the longest ladder.
What is the trade-off nobody mentions?
Size range against length range. The same five brands, counted the same day:
- PopFlex: 9 size steps, and 80% of leggings offer a choice of five height-based lengths.
- Bubblelime: 6 common size steps, and 59% of leggings offer two or more inseams — from 19" to 37".
- Senita: 7 size steps, inseam printed in the product name, but only 8% let you choose it.
- Girlfriend Collective: 11 size steps, and two or three inseams on 29 of its 33 in-stock leggings (23.75", 28", and 31" on the Compressive styles).
- Baleaf: 7 to 9 steps, length options on 2% of listings.
If your body is standard height and non-standard width, one group of brands serves you. Reverse it and the other group does. Details on picking the length are in inseam by height.
How should you shop across systems?
- Carry two numbers, not a letter. Your waist and hip in inches work at every store; "I'm a medium" works at none of them.
- Read the ladder first. Find where the notation switches before you pick a size.
- Check the stock at your size, not just the chart. A published 6XL that is sold out in every color is a chart entry.
- Watch bra sizing separately. Some sports bras use cup ranges — A–E on one line we track — rather than the letter ladder used for bottoms.
Is 1X the same as XXL?
Not automatically. They often overlap in inches but come from different grading traditions, so check the brand's own chart rather than assuming.
Why does the same brand write XXL on one page and 2XL on another?
Usually because listings were created at different times or by different suppliers. It is a cataloging artifact, and it means search results at that store are incomplete either way you type it.
Do numeric waist sizes help?
Yes, when they appear. Baleaf's outdoor pants list waist sizes from 27 to 40, which removes the guessing entirely — and is precisely why so few activewear lines use them. Stretch fabric lets brands cover more bodies with fewer SKUs.
TL;DR — Five brands, five ladders: XXS–6XL at Girlfriend, XXS–3X at PopFlex, XS–3XL plus numeric waists at Baleaf, XXS–XXL at Senita, XS–XXL at Bubblelime. Three switch notation midway. Know your waist and hip in inches, check where the ladder changes, and confirm the size is actually in stock. If you land between two, the waistband decides.
Where do sports bra sizes fit into this?
They run on a separate system, and sometimes two systems at once. Bottoms use the letter ladder; bras split into three approaches across the brands we track.
- Letter sizing only — S, M, L and up, with the band and cup rolled into one label. Fastest to shop, least precise.
- Letter size plus a cup range — PopFlex lists cup groups such as A–C, D–E and F–G alongside the size, so two people wearing the same M can order different bras.
- Cup range in the product name — one Bubblelime racerback is sold as an A–E cup style at $24.98 in XS–2XL, which tells you the support range before you open the size selector.
Median in-stock bra prices run $24.98 at Bubblelime, $34.50 at Baleaf, $35.00 at Senita, $52.00 at PopFlex and $68.00 at Girlfriend Collective. The spread is narrower than it is for leggings, and the reason is structural: a bra that fails on support fails completely, so there is less room at the bottom. Length questions for bottoms stay in inseam and height, and fit tiebreaks in fit notes.
Sources
- Size ladders and stock counts: our tally of every size option across 3,352 public listings from girlfriend.com, popflexactive.com, baleaf.com, senitaathletics.com and bubblelime.com, Sept. 8, 2026.
- Current pricing context: buy prices by store at Activewear Deals.