About ToolFactory

ToolFactory is a pen-name project for small calculators that answer one question quickly and show their work. We favor correctness, useful defaults, and plain-language limits over feature counts. The public site does not require an account, collect form submissions, or pretend an estimate is more precise than its inputs.

What we build

Every tool is hand-authored around a distinct task. The position size calculator separates cash risk from notional exposure. The drawdown recovery calculator exposes asymmetric percentage math. Our TDEE calculator, date calculator, and eSIM data estimator make their assumptions equally visible.

How a tool earns its place

We verify formulas with automated known-answer tests, keep core calculations in the browser, and cite primary or authoritative sources when the input is scientific, medical, regulatory, or device-specific. Explanations include worked examples and reference tables because a number without context is easy to misuse. Finance and health pages carry direct disclaimers rather than hiding limitations in legal copy.

The site deliberately avoids mass-generated permutations. A tool is added only when it can be meaningfully better than a generic template. Corrections are welcome through the contact page. Material updates change the date shown in the page footer.

How the site is funded

Some pages may eventually contain clearly placed advertisements or affiliate links. A qualifying purchase could pay us a commission without changing your price. Monetization never changes a formula, and sponsored links are labeled for browsers and search engines. The development build currently has reserved ad space but no active advertising or analytics requests.