Calculator Methodology
ModernWallet calculators are built to show transparent estimates using standard financial math, visible assumptions, and source-backed rules where official guidance matters.
Formulas
Loan, mortgage, investment, retirement, net worth, and budget calculators use standard financial formulas such as amortization, compound growth, cash flow, contribution growth, payoff timing, and present or future value math. Pages explain the method in plain English so readers can understand what drives the result.
Assumptions
Defaults are starting points, not predictions. Inputs such as rates, terms, expenses, returns, inflation, taxes, fees, and contribution amounts should be adjusted by the reader to match their situation. When a calculator depends on a government limit or rule, we use the most relevant official source available.
Sources
We prioritize official sources for rules and definitions: CFPB, IRS, Federal Reserve, SEC, FDIC, Department of Labor, BLS, state agencies, court or statutory materials where relevant, and official lender or provider disclosures. Third-party sources are used only when they add context that official sources do not provide.
Limits
Calculator outputs are estimates for education and planning. They are not quotes, approvals, guarantees, or personalized financial, legal, tax, or investment advice. Actual results can differ because rates, lender rules, market returns, tax treatment, and state laws change.
Updates
We review and update calculators when the underlying formula, source document, annual limit, tax rule, fee, or product assumption materially changes. Substantive updates are reflected in the visible updated date on the page.