market-sizing

name	market-sizing
description	Estimate market size using explicit market boundaries, customer or unit definitions, current evidence, top-down and bottom-up triangulation, adoption assumptions, and sensitivity ranges rather than false precision.

Market Sizing

Use when product or business decisions need a defensible estimate of addressable demand.

Procedure

1. Define the market boundary, customer or unit of demand, geography, timeframe, use case, and what the estimate will be used to decide.
2. Separate total theoretical market, serviceable market under actual product or distribution constraints, and near-term obtainable market when those distinctions matter.
3. Gather current primary or reputable secondary data for population, business counts, spend, volume, penetration, pricing, or another relevant base.
4. Build a bottom-up model from customer or transaction units wherever practical and a top-down cross-check from broader category data.
5. State every conversion, adoption, frequency, price, and eligibility assumption with its source or rationale.
6. Use ranges and sensitivity analysis for uncertain inputs rather than one over-precise headline number.
7. Reconcile conflicting estimates and explain which assumptions drive the difference.
8. End with the decision implication and what evidence would most improve confidence.

Decision rules

• A market estimate is a model, not an observed fact.
• Define the unit and boundary before searching for a market-size number online.
• Bottom-up and top-down estimates should challenge one another.
• Use precision proportional to source quality.

Quality gate

The estimate is ready when market boundaries and units are explicit, calculations are reproducible, key assumptions and source dates are visible, independent methods broadly reconcile or their differences are explained, and decision-makers can see which inputs matter most.