Unlisted Stock Valuation Calculator

What is the supplementary valuation of unlisted stock?

When a company is not listed on an exchange, there is usually no observable market price for its shares, so Korea’s Inheritance Tax and Gift Tax Act prescribes a formula to value them.
Listed shares can be valued from the closing price, but unlisted shares rarely trade, so the supplementary valuation method in Article 54 of the Enforcement Decree becomes the practical standard.

This valuation is not only the reported value for inheritance and gift tax.
It is also treated as the fair market value in related-party share transfers (for capital gains tax anti-avoidance rules and corporate wrongful-calculation rules) and as the base value for family-business succession gift-tax relief.

Korea-based, 2026 rules. This calculator reflects the Inheritance Tax and Gift Tax Act Article 63 and its Enforcement Decree Articles 54 and 56, and Enforcement Rule Article 17 (in force in 2026). It is a reference estimate for Korean tax and does not replace professional filing advice.

The core formula

1. Net profit-and-loss value per share

Take the per-share net income of the three most recent fiscal years, weight them 3 : 2 : 1 from the most recent year, and divide the weighted average by the capitalization rate of 10%.
The stronger the earning power, the higher this value becomes.

Weighted avg = (Year-1×3 + Year-2×2 + Year-3×1) ÷ 6
Earnings value = (per-share weighted income) ÷ 10%

If the three-year weighted average is negative, it is treated as zero.
The 10% capitalization rate is fixed by Enforcement Rule Article 17.

2. Net asset value per share

This is the company’s net asset value on the valuation date, divided by the total number of shares outstanding.
Net asset value equals total assets minus total liabilities, and is close to the liquidation value of what the company owns.

Net assets = Total assets − Total liabilities
Net asset value = Net assets ÷ Shares outstanding

3. The 3 : 2 weighting and the 80% floor

For an ordinary company, the earnings value and net asset value are weighted 3 : 2.
However, if that weighted average is lower than 80% of the net asset value, the value per share is set to 80% of the net asset value.

Value/share = MAX( (Earnings×3 + Net asset×2) ÷ 5 , Net asset×80% )

This 80% floor prevents shares of low-profit companies from being valued too low.

4. Real-estate-heavy companies use 2 : 3

A real-estate-heavy company, where real estate makes up 50% or more of total assets, weights earnings value and net asset value 2 : 3.
The higher the real-estate share, the more weight is given to asset value rather than earning power.

5. Net-asset-value-only cases

In the following cases, earnings value is ignored and only net asset value is used (Enforcement Decree Article 54(4)).
These are companies whose earning power is not normally formed or whose assets are unusual.

• Companies in liquidation, or where continuing the business is impractical, at the filing deadline
• Companies before start-up, within 3 years of start-up, or suspended/closed
• Companies where real estate is 80% or more of total assets
• Companies where shares of other companies are 80% or more of total assets
• Companies with a fixed term and 3 years or less remaining

6. The 20% largest-shareholder premium

Shares held by the largest shareholder and related parties get a 20% premium to reflect the control value.
However, shares of SMEs and mid-size enterprises, and of companies with losses in each of the three years before the valuation date, are excluded from the premium (Act Article 63(3)).

How to use the calculator

Step 1: Enter financial data

Enter total assets, total liabilities, real-estate value, and shares outstanding.
The net asset value and per-share net asset value are computed automatically.

Step 2: Enter three years of net income

Enter the tax-adjusted net income for the most recent three fiscal years.
Use a negative number for a loss year; the values are weighted 3 : 2 : 1.

Step 3: Set premium and special cases

Choose the company size, whether it is largest-shareholder stock, whether there were 3 straight loss years, and any net-asset-only reason.
The 80%-real-estate case is detected from the real-estate value you entered.

Step 4: Read the result

See the value per share and the total value for the number of shares held.
The result breaks down earnings value, net asset value, weighting, floor, and premium.

When it is used

Inheritance and gift tax filing

When you inherit or receive unlisted shares as a gift, this value becomes the taxable property value.
A higher value increases the base to which the 10%–50% progressive rates apply, so estimating it in advance helps planning.

Related-party share transfers

In transfers between related parties, such as a parent and child, this value is treated as the fair market value.
Trading well below or above it can trigger capital gains anti-avoidance rules or additional gift tax.

Business succession planning

The share value is also the starting point for family-business succession gift-tax relief and inheritance deductions.
Gifting when the value is low can reduce the burden, so timing around a temporary dip in earnings is sometimes used.

A worked example

Take a manufacturer with total assets of KRW 10 billion, liabilities of KRW 4 billion, 100,000 shares, and net income of KRW 1 billion / 0.8 billion / 0.6 billion over the last three years.
The value per share is built up in this order.

Net assets = 10bn − 4bn = KRW 6bn; net asset value = 6bn ÷ 100,000 = KRW 60,000
3-year weighted income = (1bn×3 + 0.8bn×2 + 0.6bn×1) ÷ 6 ≈ KRW 0.867bn
Per-share income ≈ KRW 8,667; earnings value = 8,667 ÷ 10% ≈ KRW 86,667
3 : 2 weighting = (86,667×3 + 60,000×2) ÷ 5 = KRW 76,000
80% floor = 60,000 × 80% = KRW 48,000, which is below 76,000, so the floor does not apply
An SME pays on KRW 76,000 per share; a large-company largest shareholder adds 20% to KRW 91,200

If real estate were 60% of assets, the 2 : 3 weighting would give about KRW 70,667; if net income were only KRW 0.1 billion each year, the 80% floor would set the value at KRW 48,000.
Because the result moves with earning power, asset mix, and shareholder status, it is worth comparing several scenarios.

Frequently asked questions

Q. Can I just use book net income?

A. Tax net income is derived by adding and subtracting specific items from each year’s taxable income (Enforcement Decree Article 56(4)).
It can differ from book net income, so use tax-adjusted figures and have a professional check them.

Q. Is net asset value the same as book equity?

A. Not necessarily.
Tax net asset value re-measures assets at market or supplementary value and adjusts for goodwill, deferred tax, and retained items, so it differs from book equity.

Q. Why is the value not zero when there is no profit?

A. Because the 80% net-asset floor still applies even when earnings value is zero.
If the company holds net assets, the shares are valued at 80% or more of that liquidation value.

Q. My company is an SME; does the premium apply?

A. No.
SME and mid-size company shares are exempt from the 20% largest-shareholder premium, so choose the company size correctly.

Q. Can I file with this result directly?

A. It is a reference estimate.
Actual filing needs tax adjustments, asset re-measurement, share-count adjustments for capital increases or reductions, and possible valuation-committee review (70%–130% of the supplementary value), so always have it reviewed by a professional.

Estimate your unlisted share value now

Enter the financial data and three years of net income to get the value per share and the total value at once.

Use it as a starting point for inheritance, gift, and share-transfer planning, and consult a Korean tax professional before filing.

Tax scenario inputs

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