Estimation question

How many people use Excel now?

Practice this question out loud. An AI interviewer asks it, follows up like a real interviewer would, and scores your answer. Type or speak.

What this question tests

Whether the candidate can build a top-down estimate using workforce composition and software adoption assumptions.

State scope: assume active Excel users globally, both individual and enterprise, and confirm this with the interviewer.
Estimate the global knowledge-worker population, roughly 1 to 1.2 billion office and desk-based workers, as a stated assumption.
Assume a large majority, roughly 70 to 75 percent, use Microsoft Office tools at work given Office's dominant enterprise market share.
Within Office users, assume roughly 80 to 85 percent actively use Excel specifically, since it's one of the most universally used Office apps.
Multiply: 1.1 billion times 72 percent times 82 percent gives roughly 650 million active Excel users, presented as a range around that figure.

Breaks the funnel into knowledge workers, Office adoption, and Excel-specific usage as three explicit stages.
States each conversion assumption and explains why it's reasonable given Excel's known ubiquity in office work.
Presents a final range rather than a single falsely precise number.

Guessing a single large number without a clear funnel breakdown.
Not distinguishing knowledge workers from the total global workforce, which includes many non-desk jobs.

How would this estimate change if you counted only daily active users, not occasional users?
How would growth of competitors like Google Sheets affect this estimate over time?