{"name":"PeriodFinder cross-brand period-underwear absorbency dataset","description":"Each period-underwear brand's own published absorbency claim, normalized to a single objective scale in millilitres, with a data-quality grade, the source, and the brand's verification date. No brand publishes this neutral cross-brand comparison. Figures are normalized brand CLAIMS, not independent lab measurements.","units":"millilitres","version":"2026-06-11","spine_revision":3,"source_url":"https://www.periodfinder.com/absorbency","methodology_url":"https://www.periodfinder.com/absorbency/methodology","self_url":"https://www.periodfinder.com/absorbency/data.json","license":"Free to quote, cite, and reuse with attribution to PeriodFinder and a link to the source URL.","citation":"PeriodFinder, \"Cross-Brand Period Underwear Absorbency (millilitres)\", https://www.periodfinder.com/absorbency","normalization_basis":"One regular tampon holds about 5 mL unless the brand states its own basis, anchored on the FDA 21 CFR 801.430 tampon absorbency ranges.","data_quality_grades":{"A":"the brand publishes millilitres directly","B":"converted from the brand's own tampon-equivalent claim","C":"conflicting or unconfirmed"},"key_facts":["A tier labeled \"Heavy\" spans roughly 20 to 63 mL across brands, so \"Heavy\" alone does not tell a shopper how much a pair holds.","The identical phrase \"12 regular tampons' worth\" means about 60 mL at WUKA but 100 mL at Thinx, because the brands count different tampons.","These are normalized brand claims, not independent lab measurements; grades A/B/C mark how each number was derived."],"brand_count":13,"brands":[{"brand":"Knix","basis":"super tampons x9 mL; uses live collection-page figures (higher than the brand's own blog)","verified":"2026-06-11","tiers":[{"tier":"Light","ml_min":5,"ml_max":15,"regular_tampon_equiv_min":1,"regular_tampon_equiv_max":3,"grade":"B","source":"1-3 regular tampons (ladder re-confirmed on live PLP 2026-06-11)","legacy":false},{"tier":"Moderate","ml_min":18,"ml_max":36,"regular_tampon_equiv_min":3.6,"regular_tampon_equiv_max":7.2,"grade":"C","source":"2-4 super tampons (collection page, re-confirmed 2026-06-11; blog says 2-3)","legacy":false},{"tier":"Heavy","ml_min":36,"ml_max":63,"regular_tampon_equiv_min":7.2,"regular_tampon_equiv_max":12.6,"grade":"C","source":"4-7 super tampons (collection page, re-confirmed 2026-06-11; blog says 3-6; Super Leakproof No-Show Bikini PDP states 'Now absorbs about 6 super tampons')","legacy":false},{"tier":"Ultra","ml_min":63,"ml_max":99,"regular_tampon_equiv_min":12.6,"regular_tampon_equiv_max":19.8,"grade":"C","source":"7-11 super tampons (collection page, re-confirmed 2026-06-11; one SKU states 'about 9 super')","legacy":false}]},{"brand":"Thinx","basis":"regular tampons at THINX's own 9 mL/tampon (not the ~5 mL most brands use)","verified":"2026-06-11","tiers":[{"tier":"Light (legacy ladder)","ml_min":9,"ml_max":9,"regular_tampon_equiv_min":1.8,"regular_tampon_equiv_max":1.8,"grade":"B","source":"about 1 regular tampon (Thinx states 9 mL); the classic ladder no longer appears in current product marketing (2026-06-11) - retained to translate legacy tier names","legacy":true},{"tier":"Moderate (legacy ladder)","ml_min":18,"ml_max":27,"regular_tampon_equiv_min":3.6,"regular_tampon_equiv_max":5.4,"grade":"B","source":"up to 2-3 regular tampons (legacy ladder, see Light)","legacy":true},{"tier":"Heavy (legacy ladder)","ml_min":36,"ml_max":36,"regular_tampon_equiv_min":7.2,"regular_tampon_equiv_max":7.2,"grade":"B","source":"up to 4 regular tampons (legacy ladder, see Light)","legacy":true},{"tier":"Super (legacy ladder)","ml_min":45,"ml_max":45,"regular_tampon_equiv_min":9,"regular_tampon_equiv_max":9,"grade":"B","source":"up to 5 regular tampons (legacy ladder, see Light)","legacy":true},{"tier":"All Day","ml_min":100,"ml_max":100,"regular_tampon_equiv_min":20,"regular_tampon_equiv_max":20,"grade":"A","source":"'holds up to 12 regular tampons' worth... up to 100 mL' (thinx.com/pages/how-they-work, verified 2026-06-10); All Day PDPs state 'Absorbent layers hold up to 12 regular tampons worth' (re-verified 2026-06-11) - an implied 8.3 mL/tampon basis that matches neither the common 5 mL nor Thinx's own blog's 6-9 mL definition","legacy":false},{"tier":"All Night","ml_min":100,"ml_max":100,"regular_tampon_equiv_min":20,"regular_tampon_equiv_max":20,"grade":"B","source":"'Absorbent layers hold up to 12 regular tampons worth' (all-night PDPs, verified 2026-06-11) - the identical blanket claim as All Day; no higher overnight figure is published","legacy":false},{"tier":"Overnight (Teens)","ml_min":100,"ml_max":100,"regular_tampon_equiv_min":20,"regular_tampon_equiv_max":20,"grade":"B","source":"'absorb up to 12 regular tampons (or 3 regular pads') worth of flow' (Thinx Teens PDP specs, verified 2026-06-11) - the same blanket claim as the adult line","legacy":false}]},{"brand":"Modibodi","basis":"tampons with brand-stated mL; Modibodi states the basis itself: '(Based on 5ml tampon)'","verified":"2026-06-11","tiers":[{"tier":"Light","ml_min":20,"ml_max":20,"regular_tampon_equiv_min":4,"regular_tampon_equiv_max":4,"grade":"A","source":"4 tampons / up to 20 mL (US PDP re-verified 2026-06-11)","legacy":false},{"tier":"Moderate","ml_min":30,"ml_max":30,"regular_tampon_equiv_min":6,"regular_tampon_equiv_max":6,"grade":"A","source":"'Moderate Absorbency: 30 mls, Tampons Equivalent: Up to 6 tampons (Based on 5ml tampon)' - US PDP verbatim, verified 2026-06-11","legacy":false},{"tier":"Super","ml_min":50,"ml_max":50,"regular_tampon_equiv_min":10,"regular_tampon_equiv_max":10,"grade":"A","source":"'Super Absorbency: 50 mls, Tampons Equivalent: Up to 10 tampons (Based on 5ml tampon), Perfect For: Heaviest days and Overnight' - US PDP verbatim, verified 2026-06-11","legacy":false}]},{"brand":"Saalt","basis":"tampons at ~5 mL","verified":"2026-06-11","tiers":[{"tier":"Light","ml_min":10,"ml_max":10,"regular_tampon_equiv_min":2,"regular_tampon_equiv_max":2,"grade":"B","source":"2+ light tampons","legacy":false},{"tier":"Regular","ml_min":15,"ml_max":15,"regular_tampon_equiv_min":3,"regular_tampon_equiv_max":3,"grade":"B","source":"3 tampons","legacy":false},{"tier":"Heavy","ml_min":20,"ml_max":20,"regular_tampon_equiv_min":4,"regular_tampon_equiv_max":4,"grade":"B","source":"4 tampons","legacy":false},{"tier":"Super","ml_min":40,"ml_max":50,"regular_tampon_equiv_min":8,"regular_tampon_equiv_max":10,"grade":"B","source":"8+ tampons (site standard); the Leakproof Cotton Sleep Short PDP states 'replacing a full 7 pads or 10 regular tampons of flow' (verified 2026-06-11) - the range carries the brand's own spread","legacy":false}]},{"brand":"Proof (Proof by Always)","basis":"regular tampons (stated directly)","verified":"2026-06-10","tiers":[{"tier":"Super-Light","ml_min":5,"ml_max":5,"regular_tampon_equiv_min":1,"regular_tampon_equiv_max":1,"grade":"B","source":"up to 1 light tampon","legacy":false},{"tier":"Light","ml_min":5,"ml_max":5,"regular_tampon_equiv_min":1,"regular_tampon_equiv_max":1,"grade":"B","source":"up to 1 regular tampon","legacy":false},{"tier":"Moderate","ml_min":15,"ml_max":15,"regular_tampon_equiv_min":3,"regular_tampon_equiv_max":3,"grade":"B","source":"up to 3 regular tampons","legacy":false},{"tier":"Heavy","ml_min":20,"ml_max":20,"regular_tampon_equiv_min":4,"regular_tampon_equiv_max":4,"grade":"B","source":"up to 4 regular tampons","legacy":false},{"tier":"Super-Heavy","ml_min":25,"ml_max":25,"regular_tampon_equiv_min":5,"regular_tampon_equiv_max":5,"grade":"B","source":"up to 5 regular tampons","legacy":false},{"tier":"Overnight (Super Heavy Brief)","ml_min":35,"ml_max":35,"regular_tampon_equiv_min":7,"regular_tampon_equiv_max":7,"grade":"B","source":"up to 7 regular tampons","legacy":false},{"tier":"Overnight (Hi-Rise / Boyshort)","ml_min":45,"ml_max":45,"regular_tampon_equiv_min":9,"regular_tampon_equiv_max":9,"grade":"B","source":"up to 9 regular tampons","legacy":false}]},{"brand":"Ruby Love","basis":"single absorbency, all cuts","verified":"2026-06-05","tiers":[{"tier":"Period underwear (one level)","ml_min":12.5,"ml_max":12.5,"regular_tampon_equiv_min":2.5,"regular_tampon_equiv_max":2.5,"grade":"B","source":"2.5 tampons","legacy":false}]},{"brand":"The Period Company","basis":"tampons at ~5 mL","verified":"2026-06-11","tiers":[{"tier":"Light (Thong)","ml_min":10,"ml_max":10,"regular_tampon_equiv_min":2,"regular_tampon_equiv_max":2,"grade":"B","source":"2 tampons","legacy":false},{"tier":"Medium","ml_min":20,"ml_max":20,"regular_tampon_equiv_min":4,"regular_tampon_equiv_max":4,"grade":"B","source":"'Medium absorbency... Absorbs up to 4 tampons worth of flow!' (PDP verbatim, verified 2026-06-11)","legacy":false},{"tier":"Heavy","ml_min":45,"ml_max":45,"regular_tampon_equiv_min":9,"regular_tampon_equiv_max":9,"grade":"B","source":"'Heavy absorbency... Absorbs up to 9 tampons worth of flow!' (Sleeper PDP verbatim, verified 2026-06-11; flagship styles market '10 tampons / 14 hours')","legacy":false}]},{"brand":"Bambody","basis":"tampons (Amazon-primary; brand site unreachable)","verified":"2026-06-05","tiers":[{"tier":"Leak Proof (barrier)","ml_min":0,"ml_max":2,"regular_tampon_equiv_min":0,"regular_tampon_equiv_max":0.4,"grade":"C","source":"light-medium leak barrier, no absorbent core","legacy":false},{"tier":"High Absorbency","ml_min":10,"ml_max":10,"regular_tampon_equiv_min":2,"regular_tampon_equiv_max":2,"grade":"C","source":"up to 2 tampons (Amazon listings cite up to 4 on some SKUs)","legacy":false}]},{"brand":"Aisle","basis":"regular tampons with brand-stated mL","verified":"2026-06-05","tiers":[{"tier":"Essential Thong (Light)","ml_min":5,"ml_max":5,"regular_tampon_equiv_min":1,"regular_tampon_equiv_max":1,"grade":"B","source":"1 regular tampon","legacy":false},{"tier":"Essential Brief/Hipster/Boxer (Moderate)","ml_min":20,"ml_max":20,"regular_tampon_equiv_min":4,"regular_tampon_equiv_max":4,"grade":"A","source":"4 regular tampons / ~20 mL","legacy":false},{"tier":"BOOST (adjustable, +BOOSTER insert)","ml_min":20,"ml_max":40,"regular_tampon_equiv_min":4,"regular_tampon_equiv_max":8,"grade":"B","source":"4-8 regular tampons","legacy":false},{"tier":"Super (Heavy / overnight)","ml_min":40,"ml_max":40,"regular_tampon_equiv_min":8,"regular_tampon_equiv_max":8,"grade":"A","source":"8 regular tampons / ~40 mL","legacy":false}]},{"brand":"WUKA","basis":"brand-stated mL","verified":"2026-06-10","tiers":[{"tier":"Light","ml_min":7,"ml_max":7,"regular_tampon_equiv_min":1.4,"regular_tampon_equiv_max":1.4,"grade":"C","source":">=7 mL (light-tier claim NOT first-party confirmed)","legacy":false},{"tier":"Medium","ml_min":15,"ml_max":15,"regular_tampon_equiv_min":3,"regular_tampon_equiv_max":3,"grade":"A","source":"up to 15 mL (~3 tampons)","legacy":false},{"tier":"Heavy","ml_min":20,"ml_max":20,"regular_tampon_equiv_min":4,"regular_tampon_equiv_max":4,"grade":"A","source":">=20 mL","legacy":false},{"tier":"Super Heavy","ml_min":60,"ml_max":60,"regular_tampon_equiv_min":12,"regular_tampon_equiv_max":12,"grade":"A","source":"holds up to 60 mL, 'equivalent to 12 tampons' worth' (re-confirmed on wukawear.com 2026-06-10)","legacy":false}]},{"brand":"Rael","basis":"regular tampons (conflicting claims)","verified":"2026-06-05","tiers":[{"tier":"Reusable Boyshort","ml_min":15,"ml_max":25,"regular_tampon_equiv_min":3,"regular_tampon_equiv_max":5,"grade":"C","source":"3-5 regular tampons (page: 4-5; blog: 3)","legacy":false}]},{"brand":"Hanky Panky","basis":"regular tampons at ~5 mL","verified":"2026-06-11","tiers":[{"tier":"Light","ml_min":10,"ml_max":10,"regular_tampon_equiv_min":2,"regular_tampon_equiv_max":2,"grade":"B","source":"'Light Absorbency: absorbs up to 2 panty liners or 2 regular tampons of leakage' (leakproof thong PDP, verified 2026-06-11)","legacy":false},{"tier":"Regular","ml_min":15,"ml_max":15,"regular_tampon_equiv_min":3,"regular_tampon_equiv_max":3,"grade":"B","source":"'Regular Absorbency: absorbs up to 3 panty liners or 3 regular tampons of leakage' (boyshort / French brief / V-kini PDPs, verified 2026-06-11)","legacy":false}]},{"brand":"Skims","basis":"tampons at ~5 mL (brand product copy)","verified":"2026-06-10","tiers":[{"tier":"Period Panties Thong","ml_min":10,"ml_max":10,"regular_tampon_equiv_min":2,"regular_tampon_equiv_max":2,"grade":"B","source":"three-layer gusset 'absorbs up to 2 tampons worth' (brand product copy; the static product page hides the description, so verified via search-indexed skims.com copy)","legacy":false},{"tier":"Period Panties Brief","ml_min":15,"ml_max":15,"regular_tampon_equiv_min":3,"regular_tampon_equiv_max":3,"grade":"B","source":"three-layer gusset 'absorbs up to 3 tampons worth' (brand product copy, same caveat)","legacy":false}]}]}