Ballpark — March 13, 2026
Answers to that day's 5 daily estimation questions.
About how many pounds of trash does an average US household produce in a week?
~30 lb/week
Household waste adds up quickly—often tens of pounds per week.
Liters of sweat a human can produce in a day
12 liters
Peak production during extreme heat and exercise.
Distance light travels in a single nanosecond
12 inches
Light is incredibly fast, but not instantaneous.
Pianos in New York City
20,000 pianos
A classic "Fermi problem" estimation.
Miles of blood vessels in the human body
60,000 miles
Mostly made of tiny capillaries.