About this calculator
Salary income in Japan is taxed in two layers. First, the salary deduction (給与所得控除） shrinks gross pay — at least ¥650,000 in 2025 (¥740,000 in 2026), rising with income to a ¥1,950,000 cap. Then income deductions come off: your social insurance premiums in full, a basic deduction that steps down from ¥950,000 to zero as total income rises (¥680,000 at ¥3,360,001–¥4,890,000 in 2025), and spouse and dependant deductions. The remainder is taxed on a 7-band table from 5% to 45%, plus 2.1% reconstruction tax, with the annual figure floored to ¥100.
Resident tax （住民税） is the second layer most calculators skip, and it is large: a flat 10% of a separately computed base (basic deduction ¥430,000, lower spouse/dependant amounts, and an adjustment deduction with a ¥2,500 floor) plus a ¥5,000 flat levy (¥4,000 + the ¥1,000 forest environment tax). It is levied on the previous year’s income and collected from the following June — so the figure here is next year’s resident tax estimated from this year’s income, and your first year of work has almost no resident tax at all.
How to use it
- Pick the income year and enter your monthly salary (annual salary is monthly × 12).
- Enter the social insurance premiums you actually paid (check your payslip or 年末調整 slip).
- Claim your spouse and dependants by age band.
- Add other income deductions, then read the income tax, the resident tax estimate and the take-home line.
The formula
Worked example for 2025, single, ¥5,000,000 salary, ¥750,000 social premiums, no dependants: salary deduction = 5,000,000 × 20% + 440,000 = ¥1,440,000, so employment income is ¥3,560,000. Basic deduction at that income is ¥680,000, so taxable income is 3,560,000 − 750,000 − 680,000 = ¥2,130,000. Income tax = 2,130,000 × 10% − 97,500 = ¥115,500; with reconstruction tax, floored to ¥100: ¥117,900. Resident base = 3,560,000 − 750,000 − 430,000 = ¥2,380,000; adjustment deduction ¥2,500 (the ¥50,000 floor binds); resident tax = 238,000 − 2,500 + 5,000 = ¥240,500. Take-home ¥3,891,600 — a total burden of 22.17% including social premiums.
Worked example
A single employee on ¥416,667 a month (¥5,000,000 a year) in 2025 with ¥750,000 of social premiums: income tax ¥117,900 (including reconstruction tax), resident tax estimate ¥240,500, take-home ¥3,891,600 a year, about ¥324,300 a month. Marginal rate on the next yen: 10% income tax (10.21% with reconstruction tax) plus 10% resident tax next year, about 20.21% combined.
Sources: NTA No.1410 (salary deduction table, opened); NTA No.1199 basic-deduction table (triple-corroborated, direct open pending — flagged); NTA 2026 reform page; municipal resident-tax tables (adjustment deduction formula). Verified October 2026. Last updated: October 2026.
Frequently asked questions
Why is the basic deduction not a single number?
Since the 2025 reform it is a stepped table by total income: ¥950,000 up to ¥1,320,000 of income, ¥880,000 to ¥3,360,000, ¥680,000 to ¥4,890,000, ¥630,000 to ¥6,550,000, ¥580,000 to ¥23,500,000, then ¥480,000 / ¥320,000 / ¥160,000 / ¥0 at the top. The often-quoted ¥580,000 applies only to the ¥6,550,001–¥23,500,000 band. For 2026 the bottom steps rise to ¥1,040,000 (to ¥4,890,000) and ¥670,000 / ¥620,000 above that.
Why does resident tax use different deduction amounts?
Resident tax has its own deduction table: basic deduction ¥430,000 (not the income-tax stepped table), spouse ¥330,000, general dependants ¥330,000, specific dependants (19–22) ¥450,000, elderly dependants ¥380,000 (¥450,000 if cohabiting). The adjustment deduction （調整控除） then compensates for the gap between the two tables: 5% of (the total personal-deduction gap + ¥50,000), with a ¥2,500 floor. Reusing income-tax amounts for resident tax would overstate it.
When do I actually pay the resident tax shown?
Resident tax is assessed on the previous year’s income and collected in 12 monthly instalments from the following June to May (特別徴収 via your employer). So the ¥240,500 in the example, computed from 2025 income, is collected June 2026 – May 2027. In your first year of employment, resident tax is near zero; it starts in full the second June. The calculator shows the steady-state figure.
What is not modelled here?
Housing loan tax credits, medical expense deductions, furusato nozei donation credits, side income and multiple employers (all handled at 確定申告， not 年末調整）, the income adjustment deduction for salaries over ¥8,500,000 with young dependants (up to ¥150,000 off employment income), the special dependant deduction for 19–22-year-olds with part-time income, and municipality-specific flat-levy additions. Life insurance is included only via the lump “other deductions” input (new-system caps: ¥40,000 per category, ¥120,000 total).
What changed for 2026 income?
The salary deduction minimum rises to ¥740,000 (for salaries up to ¥2,200,000; other bands unchanged, cap still ¥1,950,000), the basic deduction bottom steps rise to ¥1,040,000 / ¥670,000 / ¥620,000, and the spouse/dependant income test rises from ¥580,000 to ¥620,000. The 2026 figures are already announced and built into the year selector; figures beyond 2026 will reset with biennial CPI indexation and are deliberately not hard-coded.
What formula does this Japan Income Tax calculator use?
年収 = 月給 × 12；給与所得 = 年収 − 給与所得控除; 課税所得 = 給与所得 − 社会保険料 − 基礎控除 − 配偶者/扶養控除 − other; 年調年税額 = floor(income tax × 102.1% / 100) × 100; 住民税 ≈ 10% × resident base − 調整控除 + ¥5,000 Worked example for 2025, single, ¥5,000,000 salary, ¥750,000 social premiums, no dependants: salary deduction = 5,000,000 × 20% + 440,000 = ¥1,440,000, so employment income is ¥3,560,000. Basic deduction at that income is ¥680,000, so taxable income is 3,560,000 − 750,000 − 680,000 = ¥2,130,000. Income tax = 2,130,000 × 10% − 97,500 = ¥115,500; with reconstruction tax, floored to ¥100: ¥117,900. Resident base = 3,560,000 − 750,000 − 430,000 = ¥2,380,000; adjustment deduction ¥2,500 (the ¥50,000 floor binds); resident tax = 238,000 − 2,500 + 5,000 = ¥240,500. Take-home ¥3,891,600 — a total burden of 22.17% including social premiums. The worked example on this page applies the formula step by step with real numbers, so you can verify the result by hand.