Built 160+ micro calculator tools and the keyword data genuinely surprised me

I have been building small focused calculator tools across finance, math, health, fitness and more for a while now. The idea was simple , build one tool that solves one specific problem and put it on a keyword rich domain. Nothing fancy, nothing broad.
What I did not expect was what the keyword data would look like when I finally pulled it together.

3,600 keywords across the calculator hub. Estimated traffic potential of 341 million per month. Average keyword difficulty of 33. 1,784 of those keywords sitting at easy KD under 30 , that is 50% of the entire set at low competition.

To put that in context, a dc paycheck calculator sits at KD 4 with 1,000 monthly searches. A yarn tree calculator sits at KD 2 with 300 searches. A glomerular filtration calculator at KD 0 with 1,900 searches. Nobody is competing for these. Nobody is building dedicated tools for them either.

The pattern became obvious quickly. People search for very specific calculators constantly. Most of them land on generic calculator sites that technically answer the question but feel like an afterthought. A dedicated tool on an exact match domain with a clean interface wins almost by default.

Small boring tools with exact match domains are one of the most underrated SEO plays available right now. The competition is low, the intent is high and the barrier to entry is building something that actually works properly.

The data changed how I think about what is worth building next.