Special Benefit Advancement Calculator | Simulate Each Heir's Concrete Share

Enter the total estate value and each heir's lifetime gifts or bequests (special benefits), and this free simulator automatically calculates the deemed estate (with lifetime gifts added back), statutory share, and concrete share under Article 903 of Japan's Civil Code.

Last updated: 2026-10-17

When some heirs received lifetime gifts or bequests from the deceased, Japan's Civil Code requires "advancing" (adding back) the lifetime gifts to the estate to work out a fair division — producing a "deemed estate" from which each heir's share is calculated, after which any gift or bequest an heir received is subtracted to give their concrete share (Article 903(1)). Bequests are not added back, because they are already part of the property held at the start of inheritance. Just enter the total estate value and each heir's relationship, lifetime gifts and bequests, and this tool automatically estimates the deemed estate, statutory share, and concrete share for every heir. This is a separate topic from the "reserved portion" (forced heirship) — it applies when working out a fair split during the estate division itself.

Simulate from the estate value, heir composition, and special benefits

What is special benefit advancement?

A "special benefit" is the advantage an heir gains when they received a lifetime gift or bequest from the deceased — for example, funds for a wedding, a home purchase, or starting a business — while the other heirs received nothing comparable. If the remaining estate were simply divided according to the statutory shares without accounting for this, the heir who already received a large gift would end up better off than the others. Article 903(1) of Japan's Civil Code addresses this by "advancing" (adding back) lifetime gifts into the estate to produce a "deemed estate," calculating each heir's share from it, and then subtracting any gift or bequest an heir received to arrive at their fair, concrete share. Bequests are not added back, because they are already part of the property held at the start of inheritance.

This tool lets you simulate that advancement calculation automatically: just enter the total estate value and each heir's relationship, lifetime gifts and bequests. You'll see the deemed estate, the statutory share, the nominal share after advancement, and finally the concrete share after subtracting what each heir already received — all in one view, useful for getting a sense of the numbers before an estate division discussion or mediation.

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.

Statutory shares of inheritance and the share of a special beneficiary (Civil Code arts. 900, 903) — e-Gov Law Search (Digital Agency, Japan) Effective from 2019-07 ／ Last checked 2026-09-18

How we source and maintain these figures

How to use this tool

Enter the total estate value Enter the combined appraised value of everything the deceased left behind — savings, real estate, securities, and so on.
Add each heir and select their relationship Click "+ Add an heir" to add a row for each heir, and choose whether they are a spouse, child, or ascendant.
Enter each heir's lifetime gifts and bequests Enter the appraised value of lifetime gifts counted as special benefits and of bequests separately in each heir's row. Gifts are added back to the estate; bequests are not, because they are already included in the total estate. Leave them at 0 for heirs who received nothing.
Review the calculated results The deemed estate, statutory share, nominal share after advancement, and concrete share are all calculated automatically. Check that the totals add up correctly.
Watch for the excess beneficiary indicator If an heir's special benefit exceeds their nominal share, an "excess benefit" badge appears. How that excess is handled is a separate legal question, so review the notes below the tool as well.

Tips for getting more out of it

A "special benefit" typically means a gift for marriage or adoption, a gift as capital for a livelihood (such as funds for a home purchase or starting a business), or a bequest. Ordinary allowances or support within the scope of maintenance usually don't count.
A gift or bequest of residential real estate to a spouse is presumed exempt from advancement if the marriage lasted 20 years or more, so enter 0 for that gift or bequest in that case.
An ascendant (parent, etc.) doesn't inherit if even one child is alive or has a substitute heir. Adding an ascendant row in that situation is automatically excluded from the calculation.
When an "excess beneficiary" arises (an heir whose special benefit exceeds their nominal share), the common view is that they simply receive no further estate — they generally aren't required to return the excess.
The deemed estate and concrete share calculated here are a different concept from the value reported for inheritance tax purposes (the tax valuation before the estate is divided).

When to use this tool

An heir who provided years of caregiving estimates their fair share

If a sibling received help with home-purchase funds during the parent's lifetime while you received nothing, this advancement calculation gives you a concrete sense of what you should actually be entitled to.

Preparing figures before estate division talks or mediation

Before sitting down with all the heirs, entering each person's special benefit amount to estimate the deemed estate and concrete shares gives everyone a neutral starting point and helps keep the discussion from turning emotional.

Getting oriented before consulting a lawyer

Having a rough sense of the numbers before meeting a lawyer or judicial scrivener lets you spend the consultation time on the substantive legal questions instead.

Comparing different gift scenarios

Run the simulation multiple times with different special benefit amounts to see how the presence or size of a lifetime gift changes each heir's concrete share.

Glossary

Special Benefit (特別受益): A lifetime gift for marriage or adoption, a gift as capital for a livelihood, or a bequest that one heir received from the deceased (Article 903 of Japan's Civil Code). Ordinary allowances or support within the scope of maintenance usually don't count.
Advancement (持ち戻し): The process of recalculating the estate by adding lifetime gifts counted as special benefits back into it. Bequests are not added, as they are already part of the estate; they are only subtracted from the recipient's share. It exists to adjust the receiving heir's share so that all heirs end up treated fairly.
Deemed Estate (みなし相続財産): The value of the estate at the time of death, plus lifetime gifts counted as special benefits added back through advancement. Bequests are not added, as they are already part of the estate. This is the base figure used to calculate each heir's concrete share.
Statutory Share (法定相続分): The proportion of the estate each heir is entitled to under Japan's Civil Code. The exact fractions depend on the combination of surviving spouse, children, ascendants, and siblings.
Concrete Share (具体的相続分): The amount an heir actually receives in the estate division: their nominal share (the deemed estate multiplied by their statutory share) minus any special benefit they already received.
Contribution Share (寄与分): A separate mechanism (Article 904-2) that increases an heir's share when they made a special contribution to maintaining or increasing the deceased's assets, such as through caregiving or providing labor or funds for a family business. It works in the opposite direction from a special benefit and isn't factored into this tool's calculation.
Excess Beneficiary (超過特別受益者): An heir whose special benefit turns out to be larger than their nominal share after advancement. In principle they simply receive no further share of the estate, and are generally not required to return the excess.
Reserved Portion (遺留分): The minimum share of the estate guaranteed by law to certain heirs, regardless of what a will or lifetime gift says. It serves a different purpose and uses a different calculation method than special benefit advancement.

Frequently Asked Questions

Typical examples include gifts for marriage or adoption (such as a dowry or wedding preparation costs), gifts as capital for a livelihood (such as funds for buying a home, starting a business, or becoming independent), and bequests. Ordinary allowances or support within the scope of maintenance generally aren't treated as a special benefit.

Advancing a special benefit is about fairly calculating each heir's concrete share during the estate division itself. A reserved portion, by contrast, is the minimum share guaranteed to certain heirs even if a will or lifetime gift would otherwise deprive them of it — the purpose and the calculation method are both different.

That heir is called an "excess beneficiary" and, in principle, receives no further share of the estate (their share becomes 0). Whether they must return the excess is a disputed point, though the prevailing view is that no return is required.

Since July 1, 2019, a gift or bequest of residential real estate between spouses married 20 years or more is presumed, in principle, to be intended as exempt from advancement (Article 903, Paragraph 4). If that applies, enter 0 for that gift or bequest in this tool.

Side Note — Why does the "advancement" rule exist at all?

The special benefit advancement rule grew out of a simple concern: if one heir already received a large lifetime gift or bequest, and the remaining estate is then split equally while ignoring that fact, the result ends up unfair. For example, if only the eldest son received a large gift to start a business, and the rest of the estate is then divided equally among the siblings without accounting for that gift, the eldest son effectively ends up with more than his fair share.

The calculation works by first adding the lifetime gifts among the special benefits back into the estate to create a "deemed estate" (bequests are not added, as they are already part of the estate), then working out each heir's nominal share according to the statutory shares. Heirs who already received a gift or bequest then subtract that amount, receiving only the remainder through the estate division. This keeps everyone's final total share fair, regardless of when a gift was actually made.

Japan's 2018 inheritance law reform added a new presumption, aimed at better protecting a long-married spouse's living arrangements: a gift or bequest of residential real estate between spouses married 20 years or more is, in principle, no longer subject to advancement. This is meant to let a surviving spouse continue living in the family home with peace of mind.

The special benefit system also plays a practical role in estate division talks by making visible who received what and when. In discussions that can easily turn emotional, having a concrete calculation as a starting point helps move the conversation forward.

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