Ballpark — March 20, 2026

Answers to that day's 5 daily estimation questions.

Length of an Olympic swimming lap

50 meters

A "lap" usually refers to one length.

Total gold ever mined in human history

200,000 tons

Most of it is still in use today.

Average lifespan of a digital file (hard drive)

5 years

Hardware failure is inevitable over time.

Total emails sent every day

350 billions

Includes business, personal, and spam.

Professional football stadiums in the NFL

30 stadiums

32 teams, but 30 primary stadiums.