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Guesstimates and market sizing
Lesson 2 of 2 Math checked Last reviewed 16 June 2026 10 min

Sizing drills

Timed practice until the structure is automatic, across regions, currencies, and methods.

Key takeaways

  • Estimation gets fast only with practice.

Estimation gets fast only with practice. Do these against the clock. Say your structure out loud first, then your assumptions, then calculate, then sanity-check.

Market-sizing drill

How many households are in a UK town of 50,000 people, at about 2.5 people per household?

Market-sizing drill

Now the same 50,000 people in an Indian town, at about 4.5 people per household. How many households?

Market-sizing drill

How many liters of milk are drunk per day in a Dutch city of 1,000,000 people, if half the people drink about 0.25 liters a day?

Market-sizing drill

A pizzeria in Milan sells 200 pizzas a day at EUR 12 each and is open 350 days a year. What is its yearly revenue, in EUR?

Market-sizing drill

A Gulf country has 2,000,000 households. About 10 percent have a cat, and each spends about SAR 1,800 a year on cat food. What is the cat-food market, in SAR a year?

Market-sizing drill

Supply-side: a hair salon in Singapore has 6 chairs, is open 10 hours a day, a haircut takes 30 minutes, and the chairs are busy 70 percent of the time. How many haircuts a day?

Market-sizing drill

In a country of 1.4 billion people, 2 percent buy a product once a year at INR 500. What is the market size, in INR crore (1 crore is 10 million)?

Market-sizing drill

In the smartphone example, 63 million owners aged 12 to 59 replace every 3 years, 6 million older owners now also replace every 3 years, and 1 million people buy a first phone. How many phones a year?

Terms in this lesson
Sources for this lesson (1)
  • Recognized public explanations of case-interview concepts and frameworks
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