Spousal Inheritance Tax Reduction Calculator | First & Second Inheritance Combined
Enter the total estate value, the amount the surviving spouse actually inherits, and the number of children to estimate the tax owed after the spousal tax reduction (exempt up to 160 million yen or the spouse's statutory share), plus the combined tax through the second inheritance when the spouse later passes away.
Of the property a surviving spouse actually inherits, the amount up to whichever is larger of "160 million yen" or "the spouse's statutory share of the estate" is exempt from inheritance tax (Japan's Inheritance Tax Act, Article 19-2, the "Reduction of Tax Amount for Spouse"). However, concentrating more assets with the spouse can increase the children's tax burden at the second inheritance (when that spouse later passes away), so it's important to look beyond the first inheritance alone.
Spousal Tax Reduction Rules
| Tax-exempt ceiling | Whichever is larger of 160 million yen or the spouse's statutory share of the estate |
|---|---|
| Covers | The deceased's legal spouse (must be a legally married spouse; common-law partners do not qualify) |
| Does not cover | Children and other statutory heirs (this provision applies only to the spouse) |
Applying this provision requires certain conditions, such as the estate division being finalized by the inheritance tax filing deadline (consult a tax accountant or tax office for details).
Simulate From the Estate Value, Spouse's Share, and Number of Children
What Is the Spousal Tax Reduction?
The Spousal Tax Reduction Calculator estimates the inheritance tax owed after applying Japan's spousal tax reduction — which exempts a surviving spouse from tax on whichever is larger of 160 million yen or their statutory share of the estate — based simply on the total estate value, the amount the spouse actually inherits, and the number of children. What sets it apart is that it compares the tax due at the first inheritance against the combined total once the second inheritance (when that spouse later passes away) is factored in.
Concentrating more of the estate with the spouse lowers the tax owed at the first inheritance, but because the spousal reduction cannot be claimed again at the second inheritance, the combined total can end up worse. This calculator is a simplified simulation limited to cases where the heirs are a spouse and children, and it does not account for other deductions such as the small-scale residential land exception or the life insurance exemption. Consult a tax accountant for an exact figure.
Sources used in this calculation
Statutory figures such as tax and insurance rates come from the public bodies listed below. They change when the law is revised, so please also check the primary source before relying on the result for an important decision.
- Exemption limit for the spousal inheritance tax reduction — National Tax Agency (国税庁) Effective from 2015-01 ／ Last checked 2026-09-17
How to Use This Calculator
- Enter the total estate value Enter the taxable base — the total value of the estate — in yen.
- Enter the amount the spouse inherits Enter the amount the surviving spouse is actually set to receive from the estate division.
- Choose the number of children Select how many children will be statutory heirs. Choose 0 if there are none.
- Review the first and second inheritance results See the spouse's tax-exempt ceiling, their tax owed after the reduction, and a comparison of the combined total through the second inheritance.
Tips for getting more out of it
- Leaving the entire estate to the spouse can bring the first inheritance tax close to zero, but since the spousal reduction cannot be used again at the second inheritance, the combined total can end up worse.
- Keeping the spouse's share around their statutory portion at the first inheritance, and passing the rest to the children, is often reported to reduce the combined tax burden through both inheritances.
- A return must be filed to claim the spousal tax reduction, even if it brings the tax owed to zero (a filing requirement).
- Note that at the second inheritance the basic deduction also shrinks, since the spouse is no longer among the heirs (30 million yen + 6 million yen x number of statutory heirs).
Use Cases
Deciding how to split the estate
When negotiating how to divide the estate between spouse and children, compare the tax burden not just at the first inheritance but through the second inheritance as well.
Comparing "leave it all to the spouse" against alternatives
Estimate how the combined tax owed changes between leaving the entire estate to the spouse and keeping their share closer to their statutory portion.
Preparing before consulting a tax accountant
Get a rough sense of the reduction amount and tax owed before bringing the numbers to a professional consultation.
Anticipating the children's burden at the second inheritance
Simulate in advance how much tax the children alone would owe at the second inheritance, after the spouse has passed away.
Glossary
- Spousal tax reduction (haigūsha no zeigaku keigen)
- A provision under Article 19-2 of Japan's Inheritance Tax Act that exempts a surviving spouse from tax on whichever is larger of 160 million yen or their statutory share of the estate.
- First inheritance (ichiji sōzoku)
- The initial inheritance that occurs when one spouse passes away. In this calculator, it refers to the case where the spouse and children are the heirs.
- Second inheritance (niji sōzoku)
- The subsequent inheritance that occurs when the surviving spouse, who received assets at the first inheritance, later passes away. Only the children remain as heirs, and the spousal reduction can no longer be claimed.
- Statutory share (hōtei sōzokubun)
- The portion of the estate each heir is entitled to under Japan's Civil Code. When a spouse and children are the heirs, the spouse's share is one half, and the children collectively receive the other half.
- Basic deduction (kiso kōjo)
- The tax-exempt allowance subtracted from the taxable estate, calculated as 30 million yen plus 6 million yen per statutory heir. Fewer heirs means a smaller basic deduction.
- Quick reference tax table (sokusanhyō)
- A table published by Japan's National Tax Agency that lists the tax rate and standard deduction for each bracket of taxable inheritance amount, used to calculate the inheritance tax.
Frequently Asked Questions
Side Note — Why "Winning" at the First Inheritance Can Mean Losing at the Second
The spousal tax reduction is an extremely powerful provision — a spouse can inherit up to 160 million yen tax-free (or more, up to their statutory share, if the estate is larger). Looking only at the first inheritance, it can seem like it's always best to leave as much as possible to the spouse.
But at the second inheritance, when the spouse themselves passes away, there's no longer a spouse among the heirs. This creates a triple disadvantage: the spousal reduction itself can no longer be used, the basic deduction shrinks by one heir's worth (6 million yen), and with fewer statutory heirs to divide the estate, each child's share grows larger and can push them into a higher tax bracket. If too much is concentrated with the spouse at the first inheritance, this increased burden at the second inheritance can outweigh the tax savings gained earlier.
This is widely recognized in inheritance tax practice as "second inheritance planning," and it's recommended to simulate not just the immediate tax bill but the eventual second inheritance when dividing the estate at the first inheritance. That said, securing the surviving spouse's living expenses is another important consideration, so the split shouldn't be decided on tax minimization alone.