By combining actionable insights with your team’s expertise, we empower SaaS businesses to identify the right accounts, engage at the perfect moment, and grow with confidence—effortlessly and sustainably.
MarketSizer didn’t start as the company you see today. It began as TamCalc, a tool built by Niall O’Gorman in Dublin with one clear purpose: to help businesses calculate market opportunities using MarTech data.
At the time, our focus was on top-down market sizing—a way to analyze broad market potential for ambitious SaaS teams. But as we worked with customers, we discovered something even more impactful. The challenge wasn’t just sizing markets; it was uncovering actionable, competitive intelligence that teams could use to win, grow, and retain their ideal accounts.
What began as a straightforward market calculator evolved into what might be the largest bottom-up subscription dataset ever built, powered by more than 20 million subscription signals. That shift—from market sizing to competitive intelligence—completely redefined who we are and what we stand for.
Today, MarketSizer strives to empower SaaS teams with the insights they need to act with precision. Whether it’s identifying the right accounts, engaging at the perfect moment, or unlocking growth opportunities, we want to help our customers scale in the longterm.