Methodology

What we publish

Each calculator is a distinct intent page: unique title, inputs, engine path, methodology, worked examples, common mistakes, FAQ, and related tools. We do not publish thin city clones or keyword farms.

Engines and parameters

• Tax and social parameters live in a country pack (params.ts), not hard-coded in the UI.
• Calculation engines are pure TypeScript functions with unit tests.
• The browser runs the math client-side for instant feedback; you still must verify with official sources.
• Default illustrations use JPY amounts suitable for Japan.

YMYL and limits

Salary, tax, credit and housing topics can affect real money. Pages include disclaimers, author/review metadata where configured, and links to methodology and editorial policy. Results are educational estimates, not binding determinations from tax authorities, banks, or courts in Japan.

Quality bar

• High-intent tools include multi-block body content (method, examples, FAQ, limitations).
• Guides expand decision context beyond a single form.
• Internal links use descriptive anchors to related calculators in the same journey.
• Last content stamp: 2026-07-14 · Financial Content Team — Calcly Japan