How Much Mask-Wearing Do We Need?

Just how much mask-wearing do we need? That depends on how good our masks are. If they’re highly efficient, we can get by with fewer people wearing masks. If they’re not so great, we need a lot more people wearing them. Alan Kot has deployed a vast flotilla of Greek letters to come up with a theoretical model that produces this chart:

Each of these curves represents a disease with a particular value of R0 and shows what it would take to get R0 down to 1.0. COVID-19, for example, has an R0 of about 2.5, so take a look at that curve. On the bottom right, it shows that you can get this down to 1.0 with 100 percent of the population wearing masks that are about 35 percent efficient. At the top of the curve, you can achieve the same result with 60 percent of the population wearing masks that are 100 percent efficient. Anyplace else along the curve also works.

Fine. So how efficient are the cloth masks that we’re all wearing these days? I’m glad you asked:

The obvious problem with some of these is that, efficient or not, you’d barely be able to breathe through them. But how about silk or chiffon? They look to be about 50-60 percent efficient and are probably breathable. If we could get 80 percent adoption of masks like this, Kot says, that would be enough to get R0 below one and extinguish the the pandemic entirely.

Wear a mask! With the exception of 80 thread-per-inch quilter’s cotton, they’re all effective enough to make a difference.

UPDATE: I originally misinterpreted Kot’s chart. It’s corrected now.

SIX TRUTHS

Reclaiming power from those who abuse it often starts with telling the truth. And in "This Is How Authoritarians Get Defeated," MoJo's Monika Bauerlein unpacks six truths to remember during the homestretch of an election where democracy, truth, and decency are on the line.

Truth #1: The chaos is the point.

Truth #2: Team Reality is bigger than it seems.

Truth #3: Facebook owns this.

Truth #4: When we go to work, we're in the fight.

Truth #5: It's about minority rule.

Truth #6: The only thing that can save us is…us.

Please take a moment to see how all these truths add up, because what happens in the weeks and months ahead will reverberate for at least a generation and we better be prepared.

And if you think journalism like Mother Jones'—that calls it like it is, that will never acquiesce to power, that looks where others don't—can help guide us through this historic, high-stakes moment, and you're able to right now, please help us reach our $350,000 goal by October 31 with a donation today. It's all hands on deck for democracy.

payment methods

SIX TRUTHS

Reclaiming power from those who abuse it often starts with telling the truth. And in "This Is How Authoritarians Get Defeated," MoJo's Monika Bauerlein unpacks six truths to remember during the homestretch of an election where democracy, truth, and decency are on the line.

Truth #1: The chaos is the point.

Truth #2: Team Reality is bigger than it seems.

Truth #3: Facebook owns this.

Truth #4: When we go to work, we're in the fight.

Truth #5: It's about minority rule.

Truth #6: The only thing that can save us is…us.

Please take a moment to see how all these truths add up, because what happens in the weeks and months ahead will reverberate for at least a generation and we better be prepared.

And if you think journalism like Mother Jones'—that calls it like it is, that will never acquiesce to power, that looks where others don't—can help guide us through this historic, high-stakes moment, and you're able to right now, please help us reach our $350,000 goal by October 31 with a donation today. It's all hands on deck for democracy.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate