Korean Capital Gains Tax Calculator

This calculator works out the capital gains tax on the profit from selling a home or land in Korea. Enter the sale price, the purchase price, deductible costs such as acquisition tax and agent commission, how long you held and lived in it, how many homes you own and whether the property sits in an adjustment target area, and it walks through the gain, the long-term holding deduction, the tax base, the rate and local income tax, ending with what you keep.

Few taxes vary as widely on the same profit. A single-home household is mostly exempt, long residence earns a large deduction, several homes in an adjustment target area push the rate up, and selling within two years triggers a flat penalty rate. The calculator lets you flip each of those switches on one screen and watch the number move.

Anyone deciding whether to sell, before signing. Holding a few more months can add a year to the holding period and raise the deduction, passing the two-year mark escapes the short-term rate, and reaching two years of residence can unlock the exemption. If shifting the sale date a little changes the tax a lot, knowing that in advance is the whole point.

It also helps decide which of several homes to sell first. Selling the one in an adjustment target area first attracts the surcharge and forfeits the long-term deduction, so the order changes the total. The preliminary return is due within two months of the end of the month of sale, so knowing the figure before closing lets you plan the cash.

First the purchase price and deductible costs come off the sale price to give the gain. Then the single-home exemption is tested. Under 소득세법 제89조 and 시행령 제154조, one home held for at least two years is exempt, with two years of residence also required if the area was an adjustment target area when you bought. Above a sale price of ₩1200 million, however, only the excess is taxed: following 시행령 제160조, the gain is multiplied by (sale price − ₩1200 million) ÷ sale price to find the taxable share.

Next comes the long-term holding deduction. Table 1 of 소득세법 제95조 starts at 6% in year 3 and rises 2% a year to a maximum of 30%. A single-home household that has lived in the home for two years or more uses Table 2 instead, earning 4% a year each for holding and for residence, up to 40% and 40%, 80% combined. Multiple-home owners in an adjustment target area lose the deduction entirely. After that the annual basic deduction of ₩2.5 million comes off to give the tax base.

The rate is normally the eight-step progressive scale of 소득세법 제55조, from 6% to 45%. A two-home owner selling a home in an adjustment target area adds 20 percentage points and an owner of three or more adds 30, a surcharge that applies again from 10 May 2026. Holding under two years brings a separate flat rate: 70% under one year and 60% under two for homes, 50% and 40% for land and buildings. Where both the progressive and the flat rate apply, the larger one is used, not the sum. Local income tax of 10% on the result completes the bill.

The default on screen is a single home bought for ₩1 billion, held and lived in for ten years, and sold for ₩1.5 billion. The gain is ₩500 million, but as a single-home household only the share above ₩1200 million, one fifth, is taxable, so the taxable gain is ₩100 million. Table 2 gives 40% for holding plus 40% for residence, 80% in all, leaving ₩20 million; the ₩2.5 million basic deduction leaves a base of ₩17.5 million. In the 15% bracket the income tax is ₩1,365,000 and with local income tax the total is ₩1,501,500, 0.3% of a ₩500 million profit.

Had the owner never lived there, the exemption would still apply but the deduction would drop to Table 1's 20%, the base would rise to ₩77.5 million and the tax in the 24% bracket would jump to ₩14,124,000. A two-home owner selling in an adjustment target area gets neither the exemption nor the long-term deduction, so the full ₩497.5 million is the base and at 40% plus 20 points the bill is ₩299,816,000. Land with the same gain carries no surcharge and only the Table 1 deduction, giving ₩146,366,000.

The biggest mistake is leaving out the purchase price and costs. Acquisition tax, agent commission, legal fees and capital improvements such as replacing windows or a boiler all reduce the gain, but only with receipts; throw them away and you pay tax on that money. Next is the residence period. Table 2's residence credit looks at where you actually lived, not just where you were registered, and the exemption's residence condition depends on whether the area was an adjustment target area when you bought, so it can survive the area's later removal from the list.

Counting the holding period from the contract date is another common error. It runs from the earlier of the balance payment date and the registration date, and people have landed on the flat rate by a single day. Finally, the calculation is for Korean residents and does not cover special cases such as inherited or gifted homes, redevelopment rights or a temporary second home. If any of those apply, treat the result as a starting point and have a tax adviser confirm it.