About calculatory.app
What it is
calculatory.app is a focused suite of calculators for the small math that runs everyday life — mortgages, loans, GPA, BMI, retirement, the kinds of numbers most people approximate when they should compute.
It is not a content farm. It is not a list of links to other people's calculators dressed up with affiliate banners. Every tool on this site is built, tested, and refined by one person — to do one thing accurately and quickly, without asking for your email address.
What you get
Every calculator on calculatory.app follows the same three rules:
Live results. No Calculate button. Move a slider, change an input, the answer updates instantly. The way a real tool should behave.
Show the working. Every calculator includes the formula it uses, a worked example with real numbers, and 8 to 12 frequently asked questions about the underlying concept. You should leave understanding the math, not just the result.
No accounts, no tracking, no AI-generated filler. Calculations happen entirely in your browser. The site uses minimal analytics to understand what's broken; nothing else.
Who Makes It
Gaurav Yadav
I help leaders think better & decide smarter · Designer · Author of A CHILD in US · Creator of the CHILD Framework
calculatory.app is built, written, and maintained by Gaurav Yadav — designer, author of A CHILD in US: The Creative Thinking Handbook, creator of the CHILD Framework, mentor at eCell IIT Bombay, and founder of idaete.com.
Gaurav has spent the last decade designing systems and tools at the intersection of cognition, design, and behavior. calculatory.app is the utility companion to that work — a place where the same care for clarity and accuracy gets applied to the math people actually run.
Every formula on this site has been verified against a primary source — a textbook, a financial regulator, or peer-reviewed research — before it ships. Every page is written by Gaurav. No content is AI-generated. No content is outsourced.
The Editorial Position
Math over marketing. The calculator is the product. Everything around it — explanations, scenarios, examples — exists to make the math more usable, not to game search rankings.
Built once, refined often. Every tool starts simple and gets sharper based on what users actually need. There is no "version 1.0" that ships and gets abandoned.
Honest about uncertainty. No financial calculator can predict the future. No health calculator can replace a doctor. These tools tell you the math; they don't tell you what to do with it. That distinction is respected throughout the site.
What it isn't
calculatory.app is not a content site, an SEO play, or a vehicle for affiliate commerce. There are no sponsored calculators. There is no premium tier. There is no email gate.
Why this is free
I have spent enough years inside the design and education systems to know that good tools are often gated behind paywalls, signup walls, or worse — affiliate-driven recommendations dressed up as advice. The everyday math that quietly runs people's financial, educational, and health decisions shouldn't be one of them.
calculatory.app is my way of giving back a small part of what I have learned. The tools are free because they should be, and because the marginal cost of one more person using them is zero. No accounts. No upsells. No "premium calculator" tier.
If you find these calculators useful and want to support the work — keeping the site fast, ad-light, and helping me build new tools — you can buy me a coffee. Genuinely appreciated, never expected.
If a tool you need isn't here, email me — most additions take a weekend, and "someone asked for it" is the strongest reason a calculator gets built.