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 | 100 | A |
| All Night | 100 | B | |
| Overnight (Teens) | 100 | 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.