How this works
Japan's national income tax (所得税) runs on seven progressive brackets from 5 % to 45 %, layered over a 10 % flat resident tax (住民税 — 6 % prefectural + 4 % municipal) and a 2.1 % surtax on income tax called the reconstruction surcharge (復興特別所得税, in effect through 2037 to fund post-2011-quake rebuilding). The calculator handles both salaried and self-employed cases. For salaried workers, gross salary is first reduced by 給与所得控除 (employment-income deduction), a stepwise function that ranges from a flat ¥550,000 at low incomes up to a ¥1,950,000 cap above ¥8.5M. After that, the ¥480,000 basic personal deduction (基礎控除, for incomes ≤ ¥24M) is subtracted to get taxable income. Self-employed income skips the employment deduction and applies basic deduction only — for sole proprietors with proper bookkeeping, the actual position is usually better thanks to a 青色申告特別控除 of up to ¥650,000, which we don't model. Excludes social-insurance premiums (社会保険料控除 — typically ~15 % of gross for an employee), spouse deduction (配偶者控除), dependant deduction (扶養控除) and the per-capita resident-tax levy (~¥5,000).
The formula
Brackets 2024 (¥): 5 % up to 1.95M · 10 % up to 3.3M · 20 % up to 6.95M · 23 % up to 9M · 33 % up to 18M · 40 % up to 40M · 45 % above. 給与所得控除 schedule (gross → deduction): ≤1.625M → 0.55M · ≤1.8M → gross × 0.4 − 0.1M · ≤3.6M → gross × 0.3 + 0.08M · ≤6.6M → gross × 0.2 + 0.44M · ≤8.5M → gross × 0.1 + 1.1M · above → 1.95M flat. Basic deduction = ¥480,000 (phases out above ¥24M). Resident tax shown as a flat 10 % of taxable income — the per-capita levy of ~¥5,000 is omitted.
Example calculation
- Salaried, gross annual ¥5,000,000.
- Employment deduction = 5,000,000 × 0.2 + 440,000 = ¥1,440,000. Basic = ¥480,000. Taxable = 5,000,000 − 1,440,000 − 480,000 = ¥3,080,000.
- 所得税 = 5 % × 1,950,000 + 10 % × (3,080,000 − 1,950,000) = ¥210,500. 復興 ≈ ¥4,420. 住民税 = 10 % × 3,080,000 = ¥308,000. Total ≈ ¥522,920, effective rate ~10.5 %, take-home ≈ ¥4,477,080.
Frequently asked questions
Why does my actual paystub deduct more than this?
Social-insurance premiums (社会保険料 — health insurance 健康保険, pension 厚生年金, employment insurance 雇用保険, plus 介護保険 from age 40) typically take another ~15 % of gross for a standard employee, split between you and your employer. This calculator covers tax only. Add roughly 15 % of gross on top of the figure here for a fuller monthly net estimate, or use a Japanese 給与計算 (kyūyo keisan) tool that integrates 社会保険料 properly.
Why is resident tax shown alongside income tax?
Because residents of Japan think of tax burden as the combined figure, not the national-only one. National 所得税 is paid throughout the current year as withholding (源泉徴収) for employees or quarterly instalments for self-employed; 住民税 is then assessed by your local government in June, based on the previous year's income, and paid over the following 12 months. They're separate streams to two different governments but they hit your wallet at the same time and they're indivisible in normal salary planning. Showing them together gives the honest answer to 'how much tax do I pay?'.
What's the difference for self-employed?
No 給与所得控除. Self-employed report 事業所得 — gross revenue minus actual business expenses (必要経費) — and from that the basic ¥480,000 is the only personal deduction this calculator applies. In reality, sole proprietors who file blue-form returns get the 青色申告特別控除 worth up to ¥650,000 if they keep proper double-entry books and file e-Tax, which we don't model — add it manually if applicable. The bracket schedule is identical; only the path from gross to taxable changes.