First of all, panic-hoarding toilet paper—or anything, really—is bad. Don't do it. It makes it much harder for anyone, but especially disabled and elderly people, to buy supplies that they actually need when you hit Costco and put 100 rolls of tissue in your cart.
That said, maybe you did succumb to the fear of not being able to wipe your ass during the coronavirus pandemic. It happens to the best of us. Or perhaps you're just hoping the three rolls you have at home will last two weeks if you're forced to self-quarantine, a simple online calculator can offer a little peace of mind. The Poop Tool estimates how long your stash will stretch, based on average usage.
Using a slider, you can adjust how many people are in your household and how many rolls you currently have to see how long it will last. Probably a lot longer than you think.
"The outbreak caused global chaos in supermarkets and grocery stores, especially when it comes to toilet paper," Dmytro Spilka, the London-based creator of the Poop Tool, told me. "The main purpose of the tool is to help people realize (in an interactive way) that they don't actually need that much toilet paper to survive the quarantine, thereby allowing others, more vulnerable people to shop normally."
According to the site, the results are based on an average healthy human's daily poop output, which it claims is a little over 400 grams, or one and a half cups of poop. Sources for these numbers aren't given, but some research shows less, and it all depends on the person's diet and general health. Using fecal weight to determine sheet usage is likely flawed anyway, since, as Vice's Mack Lamoureux noted in his investigation on quarantine survival toilet paper usage, the heft of your dumps does not necessarily relate to the power of your wipage.
The Poop Tool estimates that on average, a person uses one toilet paper roll every 12 days. Lamoureux's research showed that for men, a roll could last for four weeks, but for women, it's more like a week. Unfair but that's reality.
So how much toilet paper do you really need? Maybe all the shelfposting got to you, or you were on your regular grocery run and saw people walking out of the store with arms overflowing with that sweet 2-ply, and bought a 12 pack. The Poop Tool estimates that this would last one person 144 days. This, the calculator dubs a "pretty heavy defecator."
If you stuck to normal, sane amounts of tissue and picked up a four pack, you're looking at 48 days, the tool says. That's an "easy going pooper," it says.
Say you already have an entire prepper bunker and have stored away 50 rolls for just this occasion. Good for you. That will last 300 days, and according to the Poop Tool, you are the Master Shitter.
Regardless of how exact this calculator can get, it's probably close enough to put your mind at ease, even if it's not able to predict down to the moment you hit cardboard.