所得税シミュレーター
給与所得者向けの簡易所得税・住民税シミュレーターです。概算値としてご利用ください。
税引き前の年間総支給額を入力してください
配偶者の年収が103万円以下の場合
16歳以上の扶養親族の人数
会社員の上限: 年14.4万〜27.6万円
自己負担2,000円を除き税額控除されます
海外で納付済みの税額がある場合
注意: この計算は簡易的な概算です。実際の税額は年末調整や確定申告の結果と異なる場合があります。 医療費控除、住宅ローン控除、配当控除などは含まれていません。正確な計算は税理士や国税庁のサイトでご確認ください。
This tool estimates the income tax (shotokuzei), resident tax (juminzei), and annual take-home pay you can expect from a gross salary in Japan. It walks through the same steps the National Tax Agency uses: subtract the employment income deduction, apply the basic, spouse, dependent, social insurance, life insurance, and iDeCo deductions, then run the result through the 2025 tax brackets.
It is built for foreign residents who want to sanity-check their year-end adjustment or plan a tax return without wading through Japanese tax forms. Use it to see how much an iDeCo contribution or furusato nozei donation lowers your bill, or to compare offers by turning a headline salary into a realistic monthly take-home figure.
How to use
- Enter your gross annual salary (the pre-tax total before any deductions).
- Tick the spouse box and set the number of dependents if they apply to you.
- Leave social insurance on auto-estimate (about 15% of salary) or untick it to enter the exact yearly amount from your payslip.
- Add any iDeCo contributions, furusato nozei donations, life insurance deduction, and foreign tax credit you qualify for.
- Read the calculation breakdown, your income tax, resident tax, and the take-home amount, with a bar showing how your salary splits between take-home, insurance, and tax.
FAQ
- Are my salary figures sent to a server?
- No. The entire calculation runs in your browser. Nothing you type is uploaded or stored, so you can safely enter your real income.
- How accurate is the result?
- It is a close estimate, not an official figure. It uses the 2025 employment income deduction, tax brackets, the 2.1% reconstruction surtax, and a flat ~10% resident tax. Items like medical, mortgage, and dividend deductions are not included, so your real year-end figure may differ.
- As a foreign resident, do I pay Japanese income tax?
- If you live in Japan and earn a salary here you are generally taxed like any resident. Tax residents are taxed on worldwide income, while non-permanent residents have limited foreign-income rules; this tool assumes ordinary resident salary taxation.
- What does the foreign tax credit field do?
- If you already paid tax abroad on income that is also taxed in Japan, the foreign tax credit (gaikoku zeigaku kojo) reduces your Japanese income tax to avoid double taxation. Enter the foreign tax you paid to see the rough effect.
- How does furusato nozei lower my tax?
- Furusato nozei donations are deducted from your income and resident tax beyond a 2,000 yen out-of-pocket cost. The tool subtracts the eligible amount from both taxes, so you can gauge how much a planned donation saves.