Multiple studies show that the best masks in order of effectiveness are:

  1. A well-fitting N95 mask (fits snugly to face with no gaps between your skin and the mask)
  2. A well-fitting KN95 (fits snugly to face with no gaps between your skin and the mask)
  3. An N95 mask (fits snugly to face, but not specifically fitted to wearer)
  4. A KN95 mask (fits snugly to face, but not specifically fitted to wearer)
  5. A surgical mask
  6. A cloth mask

Because not all masks provide the same level of protection, there are several things to think about like:

  • How good is the fit? If air is leaking in or out, that means COVID carrying droplets can leak in and out.
  • How likely am I to wear the mask? The best mask for you is the one that offers the most protection AND that you’ll wear.

The American Conference of Governmental Industrial Hygienists (ACGIH) released a study comparing the time it takes for COVID-19 to transmit through different kinds of masks when standing 6 feet apart.

Comparison of protection offered by different kinds of masks

The CDC has also published some helpful hacks like double masking and “knotting & tucking” to increase the efficiency of some disposable masks: https://www.youtube.com/watch?v=GzTAZDsNBe0&t=54s

Source:
https://www.acgih.org/covid-19-fact-sheet-worker-resp/ (ACGIH)
https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/types-of-masks.html (CDC)
https://www.verywellhealth.com/double-mask-knotting-loops-cdc-5113148 (Verywell Health/CDC)

Updated 05/03/2022