PartnerRoundCalculator · Case maths · free
Market sizing calculator
Lay out a market sizing as a chain of drivers, from population down to price, and see the answer update as you change each assumption. It shows the result per head as a sense check and copies the whole build as text, ready for your notes.
- Format
- Interactive
- Account
- Not needed
- Cost
- Free
How to use it
- 1Start from the population or the number of units you are sizing from.
- 2Add one driver per step: a share, a frequency or a price. Keep every number round.
- 3Read the result and the per-head figure. If either looks wrong, find the step that made it so.
- 4Copy the build and say it out loud the way you would to an interviewer.
Questions
Should I size top-down or bottom-up?
Top-down starts from a population and narrows it; bottom-up starts from one unit, such as a store or a factory, and scales it. Top-down is quicker in most interviews. Bottom-up is better when capacity limits the market. Doing both and comparing the answers is the strongest sense check.
How precise should the numbers be?
Round enough to do in your head: 65 million people becomes 60 or 70 million. Interviewers mark the logic and the sense check, not the decimal places.