About Toolsloft

Toolsloft is a library of free online calculators, converters, and formatters. Every tool does one job, loads fast, and runs entirely in your browser. No signup, no paywall, no clutter, no ads getting in the way of the answer.

Who builds this

My name is Anthony Madison. I studied Computational Mathematics at the University of Waterloo with a minor in Computer Science, and I spent three years at Google working on Vertex AI infrastructure and the Gemini API. I write every calculator here, and I write the independent check that has to agree with it before it goes live.

I mention the background for one reason. Anyone can put a formula on a web page. The question you cannot answer as a visitor is whether the person who wrote it knew what they were doing and bothered to prove it. My answer is on the How we verify page, in detail, and the check itself is public at github.com/a97madison/toolsloft-verification, so you can run it rather than take my word for it.

You can check who I am: github.com/a97madison.

Why this exists

Most calculator sites bury a simple answer under ads and popups, and none of them show their work. I wanted the opposite: single-purpose tools that are quick, clean, and, above all, correct. Getting the number right is the whole point, so I treat it as the whole point.

Accuracy is the standard

A calculator only goes live after its math passes an independent check, not just its own tests. Each tool's formula is re-derived from scratch in a separate language, from the original source rather than from my own code, and the two results have to agree. Then the real code runs against thousands of random inputs to catch anything the examples miss. Anything that fails stays hidden until I can fix it.

When a tool gives an estimate rather than an exact figure, such as the tax calculators, I say so on the page and explain the assumptions behind it. I would rather be honest about a limit than hide it.

Privacy by default

The tools process your input on your own device. The numbers and text you type are not sent to a server to be calculated. Full details are in the Privacy Policy.

Get in touch

Found a bug, want a tool that does not exist yet, or spotted a number that looks off? I want to hear it, and a wrong result gets checked and fixed. Reach me on the Contact page.