Korean Single-Home Capital Gains Exemption Calculator

This calculator tells you whether selling your only home carries any capital gains tax at all, and if so how much. The one-household-one-home exemption exists so that tax does not stand in the way of selling the home you live in and moving to another. The heart of the calculator is therefore not the tax figure but the tests: whether the holding period is met, whether the residence period is met where the home was in a regulated area when bought, and for a temporary two-home household, whether the new home was bought at the right time and the old one sold by the deadline. Each test is shown as met or not met.

Even with every test met, if the sale price exceeds ₩1.2 billion the home counts as high-value and the gain attributable to the excess is taxed. The calculator works out that tax and places beside it the tax you would have paid had any test failed, so you can see what a single condition is worth.

Anyone about to sell their only home should run it before signing. Those buying a new home first and selling the old one afterwards need the temporary two-home tests in particular: the old home must be sold within 36 months of buying the new one, and a late sale wipes out the exemption entirely. For sales on or after 1 October 2026, the window drops to 24 months where the old home is in a regulated zone and the new one, also in a regulated zone, was bought on or after 4 August 2026.

Owners of homes worth more than ₩1.2 billion need it too. Tax remains even with the exemption, and because the long-term holding deduction rate depends on whether you lived there, the figure can differ several times over. It helps decide whether to complete the residence period or delay the sale.

The exemption comes from 소득세법 제89조제1항제3호 and 시행령 제154조제1항. The base condition is a holding period of 2 years or more, and if the home was in a regulated area when acquired, a residence period of 2 years or more is added. For a temporary two-home household, 시행령 제155조제1항 treats you as a one-home household if the new home was bought at least 12 months after the old one and the old home is sold within 36 months of buying the new one. The high-value threshold is ₩1.2 billion, and the taxable part of the gain is apportioned as gain × (sale price − ₩1.2 billion) ÷ sale price.

The tax takes the taxable gain, subtracts the long-term holding deduction and the ₩2.5 million annual deduction to reach the tax base, applies the basic rates, and adds 10% local income tax. There are two deduction tables. Table 2 for one-home households adds 4% per year of holding and 4% per year of residence, each capped at 40% for 80% in total, but it requires 3 years of holding and 2 years of residence (시행령 제159조의4). That residence requirement is separate from the exemption's. Without residence, even an exempt sale gets only table 1, 2% a year up to 30%.

Take the calculator's defaults. A home bought ten years ago for ₩800 million is sold for ₩1.5 billion with ₩30 million of expenses; the owner lived there all ten years and the area was not regulated at purchase. The gain is ₩670 million and the holding test is met, so the sale is exempt. But the price exceeds ₩1.2 billion, and the ₩300 million excess is one fifth of the price, so ₩134 million of the gain is taxable. Table 2 gives 80%, or ₩107.2 million, and after the ₩2.5 million annual deduction the tax base is ₩24.3 million. That sits in the 15% band, and the total including local tax is ₩2,623,500. Had a test failed, the tax would have been ₩206,943,000, so the exemption is worth ₩204,319,500.

What if the owner never lived there and rented it out instead? The area was unregulated at purchase, so the exemption still applies, but the deduction drops to table 1 at 20%. The deduction shrinks to ₩26.8 million, the tax base rises to ₩104.7 million, the 35% band applies, and the tax is ₩23,325,500. Ten years of residence versus none is nearly a ninefold difference in tax.

The first is judging the residence requirement by whether the area is regulated now. The test is the day you bought. If the area was designated after purchase there is no residence requirement; if it was regulated when you bought, you must complete 2 years of residence even if the designation has since been lifted. The second is assuming the exemption and table 2 share the same conditions. An exempt sale without residence still gets only table 1, and the tax on the part above ₩1.2 billion grows sharply.

The third is thinking that above ₩1.2 billion the entire gain is taxed. Only the proportion attributable to the excess is. The fourth is missing the 36-month deadline for a temporary two-home household (24 months when trading up within regulated zones). Periods are counted in days, so a single day can cost the exemption; count from the dates on the property register and leave a margin. Special rules for inheritance, marriage and caring for elderly parents, waivers of the periods for expropriation or emigration, and the conditions for someone who returned from non-resident status are not in this calculator, so check them separately if they apply.