The period underwear absorbency cheat-sheet
The one-page version of our cross-brand data: which tier covers which kind of day, and what every brand's tiers actually claim in millilitres. Print it, stick it wherever you shop from, done - free, no email required.
Which tier do I actually need?
- Light day or backup: a pair claiming up to about 15 mL covers it.
- Typical daytime: the moderate band, roughly 18 to 36 mL depending on the brand.
- Heavy day or overnight: claims of 40 mL and up - the range our heavy-flow and overnight guides treat as a heavy-day buy.
- Between tiers? Go up. A too-thin pair fails publicly; a too-thick one is just a slightly thicker pair.
The trap: tier words do not travel between brands
A tier labeled "Heavy" claims 20 mL at one brand and up to 63 mL at another - a 3.1x spread behind the same word. Never carry a tier word from one brand to another - carry the millilitres. And every number on this sheet is the brand's own claim, typically from saline lab tests: the only published blood-component study measured far lower real-world capacity, so use these to compare brands, not as a leak-free guarantee.
Every brand's tiers, in millilitres
Grades: A = brand states mL directly · B = converted from the brand's tampon counts · C = the brand's own sources conflict or the claim is unconfirmed.
| Brand | Tier | Claimed mL | Grade |
|---|---|---|---|
| Thinx | All Day | 108 | B |
| All Night | 108 | B | |
| Overnight (Teens) | 108 | B | |
| Knix | Light | 5-15 | B |
| Moderate | 18-36 | C | |
| Heavy | 36-63 | C | |
| Ultra | 63-99 | C | |
| WUKA | Light | 7 | C |
| Medium | 15 | A | |
| Heavy | 20 | A | |
| Super Heavy | 60 | A | |
| Modibodi | Light | 20 | A |
| Moderate | 30 | A | |
| Super | 50 | A | |
| Saalt | Light | 10 | B |
| Regular | 15 | B | |
| Heavy | 20 | B | |
| Super | 40-50 | B | |
| Proof (Proof by Always) | Super-Light | 5 | B |
| Light | 5 | B | |
| Moderate | 15 | B | |
| Heavy | 20 | B | |
| Super-Heavy | 25 | B | |
| Overnight (Super Heavy Brief) | 35 | B | |
| Overnight (Hi-Rise / Boyshort) | 45 | B | |
| The Period Company | Light (Thong) | 10 | B |
| Medium | 20 | B | |
| Heavy | 45 | B | |
| Aisle | Essential Thong (Light) | 5 | B |
| Essential Brief/Hipster/Boxer (Moderate) | 20 | A | |
| BOOST (adjustable, +BOOSTER insert) | 20-40 | B | |
| Super (Heavy / overnight) | 40 | A | |
| Rael | Reusable Boyshort | 15-25 | C |
| Hanky Panky | Light | 10 | B |
| Regular | 15 | B | |
| Skims | Period Panties Thong | 10 | B |
| Period Panties Brief | 15 | B | |
| Bambody | Leak Proof (barrier) | 0-2 | C |
| High Absorbency | 10 | C |
Printed from www.periodfinder.com/absorbency/cheat-sheet · claims verified against the brands' own pages, data dated 2026-06-11 · CC BY 4.0 - share freely with attribution. The live table updates weekly.
Sizes are the other half of the answer - the all-brands size chart page is this sheet's sibling, and the translator turns your flow into the covering tier at every brand.
Or let the tools do it
The sheet is the whole picture. The tools narrow it to your flow and your measurement.