Japan Income Tax Calculator

The 2026 tax reform (令和7年度税制改正) created separate deduction schedules for national income tax and residence tax. Income tax now uses a dynamic basic deduction (¥950,000 for low earners, phasing down to ¥0 for very high earners), while residence tax retains the legacy ¥430,000 basic deduction. This means you have two slightly different taxable income figures.

A 2.1% surcharge on your base income tax, introduced after the 2011 Great East Japan Earthquake. It funds disaster reconstruction and is in effect through 2037. It's calculated as: Base Income Tax × 1.021, then truncated to the nearest ¥100.

Japanese tax law (国税通則法) requires specific truncation (切り捨て) — not rounding — at each step. Taxable income is truncated to the nearest ¥1,000, and the final tax amount is truncated to the nearest ¥100. This matches exactly what appears on your actual tax slip (源泉徴収票).

A statutory deduction for all salaried employees, meant to approximate work-related expenses. The 2026 reform raised the minimum from ¥550,000 to ¥650,000 and eliminated the old 40% bracket. It now ranges from ¥650,000 to a cap of ¥1,950,000 depending on your income.

It's a close approximation for most full-time employees earning ¥3M–¥12M. Japan's actual system uses Standard Monthly Remuneration (標準報酬月額) brackets with different caps for health insurance and pension. The calculator uses a simplified 15% flat rate capped at ¥18M annual income equivalent.