Ballpark — July 22, 2026

Answers to that day's 5 daily estimation questions.

Total length of the Great Wall of China

13,175 miles

The main line is shorter; this includes all branches.

Total billionaires in the world

3,428 billionaires

The US has the most, followed by China and India.

Runtime of the movie Oppenheimer

180 minutes

Christopher Nolan's longest film to date.

Calories in a stick of butter

813 calories

Pure fat is energy-dense.

Total cars in the world

1.4 billion

The majority are in North America, Europe, and China.