Everyone's building AI chatbots. I built calculators. Boring, specific, instant-result calculators. They get more traffic than most SaaS products I've seen.

The Insight

People don't Google "AI assistant." They Google "concrete cost per square foot calculator" and "how many BTUs do I need for my room" and "salary to hourly conversion."

These searches have:

High intent (someone is about to make a decision)

Zero competition from AI tools (ChatGPT can't pre-fill a form from URL parameters)

Massive long-tail volume (each calculator: 1K-50K searches/mo)

Perfect ad placement (the user is literally about to spend money)

The Architecture

Each calculator is a self-contained page with:

Inputs pre-filled from URL parameters (shareable results)

Instant calculation (no submit button, no loading state)

SEO-optimized explanation text below the calculator

Related calculators sidebar (internal linking)

Schema markup for rich snippets

The stack is deliberately simple:

HTML + vanilla JS + CSS No framework, no…