Editorial Policy

Accuracy first

Money math is unforgiving, so we treat it that way. Every financial formula is implemented with arbitrary-precision decimal arithmetic (never floating-point), and every function is covered by unit tests that check it against known, published reference values before it ships.

Transparent methodology

Each calculator includes a methodology section that states the exact formula, the assumptions we make, and the things we deliberately don’t model. If a result depends on an assumption, we show it.

Sourced data

When a tool uses real-world data — prices, rates, tax tables — we cite the primary source and show when it was last updated. We prefer official and first-party sources.

Review & corrections

Calculators and content are reviewed by the MintNumber Editorial Team, and each page shows its last reviewed date. If you spot an error, tell us at [email protected] — we investigate and fix verified issues quickly, and update the review date when we do.

Independence & disclosure

Our calculators are free and funded by advertising and affiliate partnerships. When affiliate links appear, we disclose them clearly and they never change a calculator’s math or output. We only feature products we’d consider ourselves.