About Calcistry

Calcistry builds free personal-finance calculators that show their work — the exact formula with your numbers plugged in, side-by-side scenario comparisons, and a plain-language explanation of what the result means.

Why we built this

Most online calculators hand you a single number and hide how they got it. That's fine until the number matters — a mortgage, a debt-payoff plan, a retirement projection. We think a financial tool should be transparent enough that you can verify it yourself. So every Calcistry tool displays the underlying equation, compares your options, and explains the trade-offs, with no sign-up and no email wall.

Our methodology

• Standard, published formulas. Loans and mortgages use standard amortization; savings and retirement use the future-value-of-an-annuity method; debt payoff and dividend growth use month-by-month or year-by-year simulations. Each tool shows the specific formula it uses.
• Cross-checked math. Every calculation engine is verified against known reference values and independent recomputation before publishing.
• Clear assumptions. Where a tool makes simplifying assumptions (for example, the rent-vs-buy model), we state them plainly on the page.
• Reviewed and dated. Each tool carries a "reviewed" date and its sources, and we revisit assumptions periodically.

Not financial advice

Calcistry provides educational estimates to help you understand your options. It is not financial, tax, or investment advice, and results are estimates that exclude factors specific to your situation. For decisions that matter, confirm the figures with a qualified professional.

Sources we rely on

Our explanatory content and guidance draw on public resources such as the U.S. Consumer Financial Protection Bureau (CFPB) and widely accepted financial-mathematics conventions. Rates and examples are illustrative, not forecasts.

Contact

Have a correction, a tool request, or a question about our methodology? Email hello@calcistry.com and we'll take a look.

Calcistry is an independent project. We fund the free tools through advertising; see our Privacy Policy for how ads and cookies work.