How We Build & Review Our Calculators
CalcaTools is an independent, one-team calculator site. This page explains exactly who builds it, where our formulas come from, and how we check our work — because if you’re going to trust a number from the internet, you deserve to know how it was produced.
Who runs CalcaTools
Arsalan Khan — Founder & Editor. Arsalan is a full-stack product engineer with more than a decade of experience building web software (most recently at Aranimus Tech Solutions). He is responsible for every calculator that ships on this site: the research, the implementation, the copy, and the ongoing maintenance. If something is wrong, it’s his inbox that hears about it — hello@calcatools.com.
A note on credentials — and honesty
We are engineers, not physicians, financial planners, or religious scholars — and we won’t pretend otherwise. You will not find invented reviewer names or borrowed credentials on this site. Instead, we do something more useful: every health, finance, and faith-based calculator implements a formula published by an authority you can check yourself, and the exact source is cited on the page.
- Health tools follow published guidance from the WHO, NIH, CDC, and peer-reviewed clinical literature (each page cites its specific source).
- Finance tools use the standard amortization, interest, and tax formulas published by the IRS, the Consumer Financial Protection Bureau, and the Federal Reserve.
- Islamic calculators follow documented conventions — recognised prayer-time calculation methods (MWL, ISNA, Umm al-Qura), classical fiqh rules for Zakat and inheritance — and always recommend consulting a qualified scholar for personal rulings.
- Hindu Panchang and astrology tools use the Drik-Siddhant computational model with Lahiri Ayanamsa, the same modern standard used by the Government of India’s National Calendar, presented as cultural content.
Where a decision genuinely needs professional judgment — a diagnosis, a mortgage commitment, a religious ruling — the page says so plainly and points you to the right kind of professional. A calculator gives you arithmetic, not advice.
How every calculator is built
- Research. We locate the canonical formula in a published source — a government agency, a standards body, a peer-reviewed paper, or an established reference text — and record the citation.
- Implementation. The formula is implemented in JavaScript and tested against worked examples from the source document until the outputs match.
- Documentation. Each page gets a methodology section showing the formula, a worked example, the source, and the tool’s limitations.
- Maintenance. Tools that depend on changing figures (tax tables, Nisab thresholds, festival dates) are re-checked against their sources, and every page carries a “Last updated” date.
We use modern software tools, including AI assistants, to help draft, test, and maintain pages at this scale. Everything that publishes is reviewed by a human editor first, and every formula is verified against its cited source — the tooling speeds up the work; it does not replace the checking.
Corrections
Found an error — a wrong result, an outdated figure, a broken source link? Email hello@calcatools.com with the page URL and what you expected to see. Verified corrections are fixed promptly and the page’s “Last updated” date reflects the change. This correction loop, plus the public citations, is our review process — transparent, checkable, and honest about what we are.
Frequently Asked Questions
What is the initial step in building a CalcaTools calculator?
The process begins with identifying a user need or problem that can be solved with a fast, browser-based calculation tool. This involves research into common computational challenges.
How does CalcaTools ensure the accuracy of its calculations?
Each calculator undergoes rigorous testing against known formulas and external benchmarks to verify computational precision. Our development team meticulously checks every output.
What measures are in place for user privacy during calculator use?
CalcaTools calculators are designed to operate entirely client-side, meaning no data entered into the tools ever leaves your browser or is stored on our servers. This ensures complete privacy.
Who is involved in the review process for new tools?
Our team of developers and quality assurance specialists collaboratively reviews each new calculator. This multi-stage review ensures functionality, accuracy, and adherence to privacy standards.