How Sizoru sizes a market.

Every market sizing exercise is a triangulation problem. Top-down analysis starts from a population — total spend, total addressable users, total industry revenue — and filters down to your segment. Bottom-up analysis starts from a unit — one customer’s annual spend, one transaction’s economics — and multiplies up.

Both methods are flawed in opposite directions. Top-down inherits the assumptions of whoever published the population number. Bottom-up inherits the optimism of whoever sized the unit. Used alone, either is fragile. Used together, the gap between them tells you something neither method tells you on its own: where your assumptions are weakest.

Sizoru runs both methods on every report. We don’t pick a winner. We surface the convergence — the band where both methods agree — and we flag the divergence, with reasoning, when they don’t.

A market sized by one method is an opinion. A market sized by two convergent methods is a defensible thesis.

That is the entire premise of this tool. Everything below is how we operationalize it.

Top-down begins with the largest defensible number — total industry revenue, total addressable population, total category spend — and applies sequential filters until what remains is your addressable market.

Bottom-up begins with what one customer is worth — annual contract value, transaction frequency, lifetime spend — and multiplies by the realistically reachable customer count.

A top-down number of ₹1,200 cr and a bottom-up number of ₹2,835 cr — in the example above — represent a 136% gap. That gap is not a problem. It is information. Sizoru applies a tiered convergence rule:

In the worked example, the 136% gap suggests that either (a) the top-down filter for “digitally active MSMEs willing to pay” is too aggressive — meaning bottom-up is closer to truth — or (b) the bottom-up customer ceiling of 3.5 lakh is unrealistically high — meaning top-down is closer.

We don’t pretend to know which. We surface both, explain the divergence, and let the founder defend their thesis with both methods visible.

A VC who sees a converged number has confidence. A VC who sees a flagged divergence with honest reasoning has more confidence — because they know the founder didn’t paper over the gap.

Indian market sizing is uniquely broken. Most reports — including premium ones from global firms — treat India as a single 1.4 billion consumer block, then apply uniform filters. The result is a number that is technically defensible and operationally meaningless.

Sizoru applies the India 1 / 2 / 3 framework on every report involving Indian geography. It’s a segmentation lens, not a number-cruncher — but it changes the SAM by 40 – 70% in most cases.

A SaaS startup targeting India 1 has a SAM around ~120 million addressable users — not 1.4 billion. A vernacular EdTech startup targeting India 2 has a different ceiling and a different ARPU curve. Conflating the three produces market sizes that look impressive in a deck and collapse under investor scrutiny.

Every Sizoru report involving Indian geography asks: which of the three are you actually selling to? The SAM is filtered to that segment. The investor sees a TAM that respects the country it’s drawn from.

Not all sources are equal. A government statistic and a Mordor Intelligence projection are not interchangeable, even when they appear in the same paragraph. Sizoru classifies every cited source into one of three tiers, marks each with a visible badge in the report, and weights them accordingly in the math.

Every figure in every Sizoru report carries its tier badge in the source footnote. If a number you’re about to put in your investor deck is Tier 3, you’ll know it before the VC does.

The standard market-sizing handoff looks like this: “TAM is ₹10,000 cr, SAM is ₹2,000 cr, SOM is ₹200 cr.” Every founder has put a slide like this in a deck. Every VC has nodded politely and stopped trusting the deck.

The reason: the filtering is invisible. Why did 80% of the TAM disappear into “SAM”? Why is SOM 10% of SAM and not 5% or 20%? Without the filter chain visible, the numbers are decorative.

Every Sizoru report ships a filter chain like the one above — with each filter labeled, each percentage shown, each rationale footnoted. A VC reading the report sees not just the numbers but the thinking behind the numbers. Pushback becomes specific (“I disagree with Filter 4”) instead of dismissive (“the numbers seem high”).

Specific pushback is debatable. Dismissive pushback is fatal. We optimize for the former.

Every Sizoru SOM is delivered as three scenarios — bull, base, bear — with the assumption table that produces each. The base case is the realistic 5-year projection. The bull case is the upside if execution and market timing both hit. The bear case is what happens if growth assumptions compress by 30 – 50%.

Sizoru is a product of Stolvix, an Indian technology company building investor-grade analytical tools for founders. Sizoru was created to bring institutional- grade market sizing methodology — typically gated behind ₹3 – 5 lakh consulting engagements — to the founders, consultants, and investors who need it weekly.

The dual-method framework, India 1/2/3 segmentation, and tier-rated source provenance documented above are codified in the Sizoru Market Sizing Framework v1.0.0, the proprietary methodology of Stolvix and the canonical reference applied to every report this product ships.

Questions on methodology? pot@1xl.com