Toilet paper has become one of the commodities shoppers across the world have hoarded as the coronavirus crisis forces people to stay indoors.

The website Blitzrechner.de can help reassure shoppers that they have enough. Just tell it how many rolls you have and how often you go to the toilet. You can adjust the settings for the number of wipes per trip, the number of paper squares per wipe, the number of family members in your household and how long you plan to stay home.

A person with a stockpile of 10 rolls, who uses the typical amount of paper three times a day, should survive for 53 days, it says. A message notes that this is 39 days longer than the recommended 14-day quarantine for those with symptoms.

The website, whose name means “Lightning Calculator”, has added the toilet paper number cruncher to a list of applications that can work out anything from your meat consumption to the due date of a baby.