Free financial and health calculators — built for accuracy, not advertising.
Built by Ryan Mitchell · Austin, TX
My name is Ryan Mitchell. I'm a software engineer based in Austin, Texas, and I've spent the better part of a decade working on financial software — first at a regional bank, then at a fintech startup that built loan origination tools. I know how these formulas work at the backend level, and I know how badly most consumer-facing calculators misrepresent them.
I built myclacks in 2024 because I couldn't find a single mortgage calculator that explained why the number was what it was — or that I trusted to be using the current tax brackets. So I built one myself. Then a few more. Now it's a full toolkit.
myclacks exists because important financial calculations — how much house you can afford, whether you're saving enough for retirement, what your real tax bill will be — are either buried in bank websites with upsell agendas or provided by tools that haven't been updated in years.
We build calculators that are fast, private, and accurate. There are no accounts to create, no data sent to any server, and no nudges to buy anything. Every calculation runs entirely in your browser.
Our tools cover two domains where calculation errors have real consequences:
Financial calculators — mortgages, retirement savings, taxes, loan payoff, compound interest, and salary analysis. These are topics where small errors in assumptions can mean tens of thousands of dollars in planning mistakes. We focus on tools that answer the questions most people actually face: "Can I afford this house?" and "Am I on track to retire?"
Health calculators — BMI and daily calorie estimation (TDEE). These are the same clinical screening tools used by healthcare providers as initial assessment instruments, not diagnostic tools. We present them with the same caveats clinicians use and encourage users to discuss results with a qualified professional.
Every formula we use is sourced from authoritative, publicly verifiable references. We do not invent formulas or adjust them for engagement. Below is a breakdown by calculator type:
Use the standard fixed-rate amortization formula: M = P[r(1+r)ⁿ]/[(1+r)ⁿ−1], where P is principal, r is the monthly interest rate, and n is the number of payments. This is the industry-standard formula used by lenders, verified against Federal Reserve consumer finance publications. PMI thresholds follow the Homeowners Protection Act (HPA) at the 20% equity mark.
Federal income tax brackets are sourced directly from IRS Revenue Procedures and updated annually. Standard deduction amounts follow IRS published figures for each filing status. Social Security and Medicare (FICA) rates use statutory rates of 6.2% and 1.45% respectively. State income tax is not included, as rates vary by jurisdiction and change frequently — always verify with your state's revenue department.
Projections use compound growth with user-specified return rates. The default 7% annual return reflects the approximate historical real return of a diversified US stock index (S&P 500 historical average ~10% nominal, minus ~3% inflation). The 4% withdrawal guideline derives from the Trinity Study (Cooley, Hubbard, and Walz, 1998, updated 2011) — the most widely cited academic research on sustainable retirement withdrawal rates.
Follows the World Health Organization (WHO) BMI classification system: BMI = weight(kg) ÷ height(m)². Category cutoffs (18.5, 25.0, 30.0) are the international WHO standards used in clinical practice globally. We explicitly note the limitations — BMI does not distinguish between fat mass and lean mass, and has reduced accuracy for athletes, older adults, and certain ethnic groups — consistent with WHO and CDC guidance.
Uses the Mifflin-St Jeor equation, the formula recommended by the Academy of Nutrition and Dietetics as the most accurate predictive equation for resting metabolic rate in most adults (Frankenfield et al., 2005, Journal of the American Dietetic Association). Activity multipliers follow standard TDEE conventions used in sports science and dietetics research.
Tax rates, contribution limits, and financial regulations change annually. We review and update all rate-dependent calculators at the start of each calendar year, or whenever the IRS or relevant regulatory agency publishes updated official figures. Current tax data reflects 2026 IRS published brackets and standard deductions.
If you spot a calculation that appears incorrect, please contact us. We take accuracy reports seriously and typically investigate within 2 business days.
myclacks provides general educational information only. We are not a financial advisory service, a licensed tax preparer, a lender, or a medical provider. Our calculators produce estimates based on the inputs you provide and standard formulas — they do not account for your complete financial picture, specific tax situation, or individual health history.
Before making any significant financial decision — buying a home, changing retirement contributions, or adjusting tax withholding — consult a qualified financial advisor, CPA, or licensed professional who can review your complete situation. See our full Terms and Conditions.
All calculations happen locally in your browser using JavaScript. No inputs — your income, loan amount, health metrics, or any other data — are transmitted to our servers or stored anywhere. We do not require accounts, do not use tracking pixels, and do not sell data. The only third-party service we use is Google AdSense for advertising, which operates under Google's Privacy Policy. See our full Privacy Policy for details.
Questions about our methodology, accuracy issues, or general feedback — we read every message.