CalcaTools

About CalcaTools

Our mission

CalcaTools is a free, browser-based calculator library covering finance, health, math, everyday tasks, festive planning, and faith-based calculations. We started this site because most calculator websites bury the answer under banner ads, registration walls, and slow-loading forms. We wanted something different: clean, fast, accurate, and respectful of your privacy.

What we publish

We currently maintain 400+ free calculators across seven topical categories:

  • Finance Calculators — mortgage, auto loan, compound interest, retirement, salary, sales tax, currency, and 18 more financial planning tools.
  • Health & Fitness Calculators — BMI, BMR, TDEE, body fat, ideal weight, pregnancy, ovulation, pace, calorie, and macro calculators grounded in WHO, NIH, and ACSM formulas.
  • Math Calculators — percentage, fraction, statistics, algebra, geometry, probability, and number-theory tools used by students and professionals.
  • Everyday Calculators — date arithmetic, GPA, fuel cost, electricity cost, GDP, height, hours, and dozens more utility tools.
  • Christmas Calculators — Christmas countdown, Secret Santa generator, turkey cooking time, tree-light electricity cost, Naughty-or-Nice, and gift-budget planners.
  • Islamic Calculators — Zakat, Nisab, prayer times, Qibla direction, Hijri date converter, Ramadan and Eid dates, Faraid inheritance, Hajj cost, and more, built against authentic Shariah formulas.
  • Hindu Calculators — Janam Kundali, Kundali Matching, Rashi, Nakshatra, Mangal Dosha, Vimshottari Dasha, Panchang, Rahu Kaal, Choghadiya, Vastu, gemstone, and festival-date calculators on Drik / Vedic astronomical formulas.

Who we are

CalcaTools is operated and maintained by a small, independent team founded by Arsalan Khan. Every calculator is checked against its published source formula before publication and re-checked periodically against the latest published standards.

Editorial standards

  1. Cite the formula. Every tool documents the exact formula, the publishing body (e.g. WHO, IRS, NIST, NHTSA, ACSM, AIPRD, AMSI), and the version we follow.
  2. Show the work. Each calculator includes a “Quick reference” table mapping inputs to formula to output, plus a methodology section.
  3. Review quarterly. Each tool carries a “Last reviewed” date so you can see when the maths and methodology were last verified.
  4. Disclose limits. Where a calculator is an approximation (for example, U.S. federal income tax, which has hundreds of edge cases), we say so up front and link to the authoritative source.
  5. Stay neutral. We do not write affiliate-driven recommendations. We are a calculator hub, not a product comparison site.

Who checks the maths

CalcaTools is built by a small independent team led by founder Arsalan Khan — engineers, not doctors or financial planners, and we don’t pretend otherwise. Instead of unverifiable sign-offs, every YMYL calculator implements a formula from a published authority (WHO, NIH and CDC for health; IRS, CFPB and the Federal Reserve for finance; classical fiqh sources for the Islamic tools; the Drik-Siddhant Panchang standard for the Hindu tools) and cites that source on the page, so you can verify it yourself. The full process is documented on our How We Build & Review Our Calculators page.

How we keep this free

CalcaTools is supported by display advertising via Google AdSense and by CalcaTools. We do not charge for any tool, ask you to register, or paywall any feature. We do not sell user data — see our Privacy Policy for details.

What we are not

Our calculators are educational and informational. They are not a substitute for licensed professional advice. For financial decisions consult a financial advisor; for medical decisions consult a healthcare professional; for legal or tax matters consult an attorney or CPA; for religious rulings consult a qualified scholar in your tradition. See our Disclaimer.

Contact

Found a bug, want a new calculator, or have a correction to suggest? Email hello@calcatools.com or visit our contact page. We answer within two business days.

If you have any questions about calcatools or our mission, please reach out via our Contact page.

Frequently Asked Questions

What is CalcaTools?

CalcaTools provides fast, private, browser-based calculators and tools designed for efficiency and user data protection.

How does CalcaTools protect user privacy?

CalcaTools operates entirely within your browser, ensuring no data is stored on our servers, thereby maintaining your privacy.

What is the mission of CalcaTools?

Our mission is to offer quick, reliable, and privacy-focused calculation tools that are accessible directly through your web browser.