An open resource for founders, investors & operatorsPRIVATE MARKETS, EXPLAINED.
Market sizingFREE ACCESS

Top-Down Market Cross-Check Calculator

Narrow a sourced annual market estimate with explicit scope adjustments.

6 min guideTransparent methodologyUSDGo to calculator ↓
01 / UNDERSTAND THE CONCEPT

A market report is a cross-check, not a customer plan.

Top-down sizing narrows a reported market to the geography and product segment relevant to a business. Each percentage must have a defensible meaning and apply to the population remaining after the prior filter.

The final market-share assumption is particularly weak without supporting sales evidence. This page exists to reconcile industry totals with a bottom-up model, not to turn an arbitrary small percentage into a revenue forecast.

02 / THE MATHEMATICS

The formula, made clear.

Scoped market = reported annual market × geographic share × conditional segment share; scenario revenue = scoped market × share
Conditional segment share
Share within the already-filtered geographic market; avoid overlapping filters.
Scenario share
A hypothetical position in the scoped market, not a measured capture probability.
03 / A WORKED EXAMPLE

Put the numbers in context.

A $5,000,000,000.00 annual market narrowed to 10% geography and 20% relevant segment becomes $100,000,000.00. A 2% scenario equals $2,000,000.00 annually.

Illustrative scenario · USD
InputExample value
Reported annual market revenue$5,000,000,000.00
Relevant geographic share10%
Relevant segment within that geography20%
Scenario share of the scoped market2%
Scenario annual revenue$2,000,000.00
MODEL BOUNDARIES

What this calculation assumes

Comparable annual revenue definitions, source date and pricing. Filters are sequential and evidence-based. The model cannot validate the market report, competitive response or the scenario share.

FROM UNDERSTANDING TO ACTION

What to consider next.

Rebuild the implied revenue from named customer segments, pricing and sales capacity. Investigate large differences between methodologies.

How we approach financial models →
THE OAKSHORE NETWORK

Understand the mechanics.
Then enter the market.

Oakshore connects verified founders and investors through a private, thesis-aligned market network.

Explore Oakshore