Methodology & editorial policy

We use primary sources, not secondary summaries. Where a calculation depends on a published rate, limit or threshold, that value is taken from the body that sets it and is cited on the calculator page itself.

• •Tax and retirement — Internal Revenue Service (IRS) publications, revenue procedures and form instructions
• •Mortgages and consumer lending — Consumer Financial Protection Bureau (CFPB), Federal Housing Finance Agency (FHFA), HUD
• •Health and body metrics — Centers for Disease Control and Prevention (CDC), World Health Organization (WHO), National Institutes of Health (NIH)
• •Inflation and wages — Bureau of Labor Statistics (BLS)
• •Social Security and Medicare — Social Security Administration (SSA) and CMS
• •Investment concepts — SEC Investor.gov and Federal Reserve statistical releases

Standard financial mathematics — amortization, present and future value, internal rate of return — follows conventional published formulas, which are shown in full on each calculator page so you can verify the arithmetic yourself rather than take the output on trust.

Content is written and fact-checked by the CalcProLabs editorial team. We want to be precise about what that means, because the internet is full of vague authority claims: it is a small team, and we do not claim to be licensed accountants, attorneys, financial advisers or clinicians.

What we do claim is method. Every published figure is traced to a primary source and linked, every formula is shown in the open, and every page states the year its figures apply to so that outdated numbers are visible rather than hidden. Where a topic requires professional judgement about your individual circumstances, we say so and recommend a qualified professional instead of substituting for one.

Each calculator page carries a “last updated” date. That date reflects the most recent review of that page’s content and figures.

• •Tax calculators are reviewed when the IRS publishes annual inflation adjustments, and again if legislation changes rates, brackets or limits mid-year.
• •Contribution and benefit limits (401(k), IRA, HSA, Social Security) are reviewed on the annual publication cycle of the agency that sets them.
• •Health thresholds are reviewed when the issuing body revises its guidance.
• •Mortgage and lending content is reviewed when conforming limits, insurance rules or disclosure requirements change.

Every calculator here is a model, and every model simplifies. Results are estimates for education and planning, not professional advice, and not a substitute for advice specific to your situation.

• ✗Tax estimates use federal rules and common assumptions. They cannot capture every credit, phase-out, state and local rule, or filing circumstance.
• ✗Investment projections assume a constant rate of return. Real markets do not deliver returns smoothly, and sequence of returns matters.
• ✗Health metrics are population-level screening tools. They cannot assess an individual's body composition, medical history or medications.
• ✗Legal and settlement estimators reflect general patterns, not the facts of any particular case or jurisdiction.
• ✗Insurance and benefit estimates depend on underwriting and eligibility rules that vary by carrier, plan and state.

Calculators and editorial content are produced independently of advertising. Advertisers do not review content before publication and cannot influence a calculation, a recommendation, or the conclusion of any page. Where a page contains an affiliate or partner link, the calculation itself is unaffected by it.

Your inputs are processed in your browser. Calculations run client-side and the figures you enter are not transmitted to us — see our privacy policy for detail.

Corrections. If you believe a formula, figure or citation on this site is wrong, tell us and we will check it against the primary source. Where we are wrong we correct the page and update its review date. Accuracy complaints are treated as the highest priority feedback we receive.