Thinx

Thinx's sizing and absorbency, translated onto the same scale as every other brand - so you can shop it (or leave it) with a fair comparison.

How Thinx sizing runs

Runs true to size. Thinx states styles are "completely true to size" and recommends following the HIP measurement (measured at widest point, derriere included) for the most accurat

Size	Hip	Waist
XS	35–36"	25–26"
S	37–38"	27–28"
M	39–40"	29–30"
L	41–42"	31–32"
XL	43–44.5"	33–34.5"
X (plus)	43–44"	36–37"
1X	45–47"	38–40"
2X	49–51"	42–44"
3X	53–55"	46–48"
4X	57–59"	50–52"

Know your hip measurement? Get your size in every brand at once.

What Thinx's tiers really hold

Heads up: Thinx counts a 'regular tampon' as 9 mL, so its tampon labels look smaller per-tampon than brands using ~5 mL. Normalized to mL here for honest comparison. Separately, the brand's current flagship claim ('up to 12 regular tampons / up to 100 mL' on how-they-work) implies 8.3 mL/tampon - matching neither the common 5 mL basis nor the brand's own blog (6-9 mL) - and is not reconcilable with the classic tier ladder below (Super = 45 mL). The identical phrase '12 regular tampons' worth' means 60 mL at WUKA and 100 mL at Thinx. v3 finding (2026-06-11): the SAME 'up to 12 regular tampons' worth' claim is printed on All Day PDPs, All Night PDPs, and Teens PDPs alike - one blanket maximum across the whole period line, with no per-tier capacity ladder in current product marketing.

Light (legacy ladder)9 mL Data quality grade B, converted from tampon counts
Moderate (legacy ladder)18–27 mL Data quality grade B, converted from tampon counts
Heavy (legacy ladder)36 mL Data quality grade B, converted from tampon counts
Super (legacy ladder)45 mL Data quality grade B, converted from tampon counts
All Day100 mL Data quality grade A, brand publishes mL
All Night100 mL Data quality grade B, converted from tampon counts
Overnight (Teens)100 mL Data quality grade B, converted from tampon counts

Claims verified 2026-06-11 · Millilitres are the brand's own published claims, normalized - methodology. Cross-brand view: the full table.

Thinx catalog (32)

Thinx

All-Day Bikini

All Day· 100 mLData quality grade A, brand publishes mL

Sizes 9-10–15-16

$19

How Thinx sizing runs

What Thinx's tiers really hold

Thinx catalog (32)

All-Day Bikini

Active Mesh Bikini

All-Day Brief

Everyday Comfort Lace Brief

Everyday Comfort Bikini

Active Mesh Bikini

Everyday Comfort Brief

Everyday Comfort Hi-Waist

Basic Hi-Waist

Basic Brief

Overnight Boyshort

Thong

Butterfly Shorts

Comfort Stretch Hiphugger

Ultra Soft Brief

Breathable Hiphugger

Hiphugger

Comfort Stretch Hi-Waist

Ultra Soft Hi-Waist

Lace Hi-Waist

Ultra Soft Boyshort

Soft Smoothing Hi-Waist

3-Pair All-Day Brief Kit

3-Pair All-Day Bikini Kit

Ultra Soft Sleep Shorts

Cotton Starter Set

Rotation Set

Comfort Stretch Hiphugger Set

Hiphugger Lovers Set

Make the Switch Set

Comfort Stretch Hi-Waist Set

Cotton Overnight Set