About Calc Tani
Calc Tani is a free utility site hosting 16 everyday Korean calculators in one place. Our mission isn't just to give you a number — it's to explain why the number is what it is.
Why We Exist
In late 2025, the site operator was comparing take-home salary across several Korean calculators before a job change — and found differences of KRW 300,000+ for the same input. Some sites used outdated 2023 tax rates; others ignored the pension cap. Calc Tani exists because "convenient" is not enough. Calculators must be accurate.
Operating Principles
- Up-to-date rates — We apply 2026 rates for national insurance, the simplified income tax table, and retirement tax deductions, updating within 30 days of legal changes.
- Local-only computation — All sensitive inputs (salary, health data) are computed in your browser. Nothing is sent to our servers.
- Verifiable formulas — Each calculator's formula and source is documented on the Methodology page.
- Core features stay free — Display advertising covers our costs, but no calculator feature is ever gated or hidden behind ads.
How We Verify Content
Before publishing a new calculator or guide, every item goes through:
- Official cross-check against NTS, National Pension Service, and Health Insurance Corporation data.
- Same-input comparison against at least 3 competitor calculators; significant discrepancies trigger root-cause analysis.
- Boundary testing (zero, max, upper/lower thresholds).
- Bilingual content review (Korean and English).
Recent Updates
- 2026-04-15 — Launched the guide hub (8 articles published).
- 2026-03-24 — Sitemap and SEO metadata overhaul; added missing canonical coverage.
- 2026-02-19 — Updated for 2026 insurance rates and retirement tax deductions.
- 2025-12 — Added the 16th calculator (Stock Return).
Contact
We welcome bug reports, calculation disputes, and requests for new calculators. Contact page leads directly to the operator.