Size guide
Measurements are for your body, not the garment. Measure over the underwear you'd train in, and use the fit notes below to decide between two sizes.
Last updated August 1, 2026
Size chart
| Size | US | Bust | Waist | Hip |
|---|---|---|---|---|
| XS | 0-2 | 31-32" | 24-25" | 34-35" |
| S | 4-6 | 33-34" | 26-27" | 36-37" |
| M | 8-10 | 35-36" | 28-29" | 38-39" |
| L | 12-14 | 37-39" | 30-32" | 40-42" |
| XL | 16-18 | 40-42" | 33-35" | 43-45" |
Our size range goes from XS to XL, equivalent to US 0 to 18. The pieces are cut on Brazilian blocks, which sit slightly higher on the waist than most American activewear. This is deliberate, and it's why the waistband stays put during squats.
How to measure
Use a flexible measuring tape and keep it snug, but never tight. If you can fit two fingers under the tape, it's too loose; if it leaves a mark, it's too tight.
Bust
Measure around the fullest part of your bust, keeping the tape level and parallel to the floor. Wear the bra you normally train in.
Waist
Measure at the narrowest point, usually just above your belly button. Breathe out normally. Don't pull the tape tight.
Hips
Stand with your feet together and measure around the fullest part of your hips and seat.
Inseam
Measure from the crotch seam down the inside of your leg to where you want the hem to sit.
How each piece fits
Same size, different purposes. A compression legging and a relaxed tee aren't meant to sit on the body the same way, so read the note for the category you're buying.
Leggings
Our leggings run true to size, with a high, wide waistband. Between two sizes, size down for firmer compression or stay in your usual size for everyday wear.
Shorts
Our shorts run true to size. The inner short is cut slightly longer than the outer layer so it won't ride up mid-workout.
Sports bras
Our bras run true to size in both band and cup. If the band feels loose between two sizes, size down. Support comes from the band, not the straps.
Tees
Relaxed fit. Size down for a closer fit.
Accessories
One size, made to sit comfortably without digging in.
Between sizes?
For leggings and shorts, size down if you want firm compression and stay true to size for everyday wear. For sports bras, size down if the band feels loose: the support comes from the band, not the straps. For tees, size down for a closer fit.
If you're still unsure, order both sizes and return the one that doesn't fit. Exchanges are free within 30 days, and it costs you nothing to be sure.
You can also email support@aerafitwear.com with your measurements and the piece you're looking at. We'll tell you which size we'd send, even when the honest answer is that the piece isn't right for what you need.
Full return and exchange details are on the Shipping & returns page.