Target
Hidden category
All in Motion Girls' Plus leggings & sets
- Leggings, bike shorts, sports bras in plus
- Cheap, soft fabric, wide availability
- Matches Cat & Jack size 18 swim
- Best colors sell out fast
Girls plus size activewear, leggings and sets that actually fit
The same size gap that hits swimwear hits leggings, sports bras and rash guards too. Good news: activewear follows the same numeric chart as swim, so once you know her size, these are the brands that carry it in plus.
Short answer for plus girls' active:
Target All in Motion and Old Navy Active for everyday, Athleta Girl for premium, and SwimHer for rash-guard sets.
Prefer more coverage? We flag modest, higher-coverage styles (rash guards, swim shorts, full one-pieces) on every list.
Where to buy plus girls' activewear
Leggings, sports bras, rash guards and matching sets, cut for a fuller tween or teen build.
Walmart
Hidden category
Wonder Nation Active Girls Plus (7–18)
- Lowest price; leggings & active tops to 18
- Same Girls Plus chart as their swim
- In stock most of the year, not just summer
- Thinner fabric; basic styling
Old Navy
Hidden category
Girls' Plus PowerSoft leggings & sets
- Soft, durable PowerSoft fabric
- Girls' Plus cut with full size range
- Constant sales and bundle deals
- Plus sizes mostly online, not in store
Athleta Girl
Hidden category
Athleta Girl leggings, sets & sports bras
- Best fabric and support, built to last
- Inclusive, body-positive sizing & cuts
- Great for serious sports and dance
- Premium price; top sizes sell out
Amazon
Hidden category
“Girls plus size leggings” & active sets
- Biggest range, including dancewear & leotards
- Fast Prime delivery; easy size filtering
- Read recent reviews for true fit
- Seller sizing varies widely
SwimHer
Hidden category
Extended-size rash-guard active sets
- Long-sleeve rash guards for sun + coverage
- Crossover from swim to beach activewear
- Stocks its own extended sizes
- Swim-focused; not full gym range
Buttons open each brand's live results in a new tab. We don't hold inventory; prices and stock are set by each store.
Activewear sizing, the short version
The good news: you already know her size from swim. Activewear uses the same numbers, with a little stretch room.
Same numeric chart as swim
An 18 or Plus in a brand's swim almost always equals an 18 or Plus in its leggings and sets. Start there.
Stretch gives you wiggle room
If she is between sizes, size down for compression (sports) or up for comfort (everyday). Activewear forgives more than swim.
Sports bras: band width matters most
For a developing tween, choose a wide band with full coverage over a thin trainer. That gives real support during activity.
Need her swim size first? See the girls size 18 sizing chart.
Plus activewear: questions answered
Does girls' activewear use the same sizing as swim?
Mostly yes. Girls' activewear follows the same numeric chart as swimwear, so an 18 or Plus in swim usually maps to an 18 or Plus in leggings and sets from the same brand. Stretch fabric is more forgiving, so if she is between sizes you can size down for compression or up for comfort.
Where can I find girls' plus size leggings?
Target's All in Motion, Old Navy's active line and Walmart's Wonder Nation Active all carry girls' plus leggings cut for a fuller build, and Amazon has the widest selection. Athleta Girl is the premium option with the best fabric, though its top sizes sell out faster.
What about sports bras for a developing tween?
Look for girls' or junior plus sports bras with wider bands and full coverage rather than a thin training shape. Target, Old Navy and Aerie all carry supportive options. A racerback with a wide band gives the most support for an active, developing tween.
Are there plus size dancewear and leotards for tweens?
Yes, though they are harder to find. Amazon and specialty dancewear sellers carry plus and extended girls' leotards, and a snug activewear tank with leggings works for many classes. Check the studio's dress code, then match by chest and torso measurement.