Definition
Market sizing based on realistic units × price rather than broad estimates.
Examples
Bottom-up sizing used number of programs × ACV.
Origin
Modern business/startup term; used as practical shorthand in product, growth, and investing.
Use it in Nautis
Track bottom-up sizing alongside everything else in your startup.
Nautis brings planning, fundraising, finance, and operations into one AI-native workspace — so concepts like bottom-up sizing stop being spreadsheet trivia and start showing up where decisions get made.