Sizing
Thinx runs true to size; Knix tends to run small (many people size up). Both brands size from your hip measurement, so rather than converting one brand's size into the other's, the size finder gives you your size in each directly.
Thinx: 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
Knix: Brand labels core styles "True to Size" on product pages (e.g. Essential High Rise). However, customer reviews consistently report the leakproof styles run small / recommend sizing
Quick answers
- Is Thinx or Knix more absorbent?
- Thinx and Knix top out at nearly the same claimed capacity - about 100 mL for Thinx and 99 mL for Knix at their highest current tiers. The bigger difference is how they label the steps below the top: compare the millilitres at each tier rather than the words, because a tier name like "Heavy" is not the same capacity at the two brands. And remember these are saline-lab maximums, not leak-free guarantees - the only blood-component study measured far lower real capacity.
- Do Thinx and Knix use the same absorbency labels?
- No. Thinx publishes 3 current tiers (100 mL across the range) and Knix publishes 4 (15–99 mL). Even where the words overlap, the millilitres differ, which is exactly why this page compares them in millilitres with a data-quality grade on every number.
- How do Thinx and Knix sizes compare?
- Thinx runs true to size; Knix tends to run small (many people size up). Both size from your hip measurement, so the size finder gives your size in each brand directly rather than guessing from the other brand's number.
Skip the comparison - get your answer
Tell the translator your flow and it gives the covering tier at both Thinx and Knix. Tell the size finder your hip and it gives your size in each.