Capital Gains Tax Calculator

Capital gains tax is levied on the profit from selling assets such as real estate, stocks, and derivatives. In South Korea, real estate capital gains tax is one of the most significant taxes, potentially ranging from millions to hundreds of millions of won when selling a home. As of 2025, capital gains tax rates are progressive, ranging from 6% to 45%, with an additional 10% local income tax.

Accurate calculation of capital gains tax is essential when trading real estate. Without pre-calculating taxes, unexpected tax burdens can significantly reduce actual net profits. For example, when selling a home purchased for 300 million won at 500 million won, the capital gain of 200 million won could result in over 50 million won in taxes.

One-home households meeting certain requirements can be exempt from capital gains tax. As of 2025, homes valued at 1.2 billion won or less, held and resided in for at least 2 years, are completely tax-exempt. Understanding these exemption requirements precisely can save tens of millions of won in taxes.

Using a capital gains tax calculator allows easy computation of complex tax rates and deduction items. Simply input acquisition price, transfer price, and holding period to immediately verify estimated tax amounts, greatly assisting in financial planning before real estate transactions.

The 2025 capital gains tax follows a progressive rate structure. Tax bases up to 14 million won are taxed at 6%, 14-50 million won at 15%, 50-88 million won at 24%, 88-150 million won at 35%, 150-300 million won at 38%, 300-500 million won at 40%, and over 500 million won at 45%.

Progressive taxation does not apply a single rate to the entire amount but applies different rates to each bracket. For example, with capital gains of 100 million won, the first 14 million is taxed at 6%, the next 36 million at 15%, and the remaining 50 million at 24%. This calculation results in approximately 15.6 million won in tax, plus 10% local income tax for a final amount of about 17.16 million won.

Multiple home owners face heavier taxation. Owners of 2 homes in adjustment target areas have an additional 20 percentage points added to the basic rate, and 3+ home owners have 30 percentage points added. This can push the maximum rate up to 75%. As of 2025, 25 districts in Seoul including Gangnam-gu, Seocho-gu, and Songpa-gu are designated as adjustment target areas.

Long-term holding deductions reduce capital gains by certain percentages based on holding period. Starting at 12% for 3+ years, the deduction reaches up to 50% for 15+ years. For one-home households, additional deductions based on residence period can bring the total to 80%.

Capital gains tax must be filed and paid within 2 months from the end of the month of transfer. Failure to file on time results in a 20% non-filing penalty plus late payment penalties. Therefore, accurate tax calculation and timely filing are crucial.

The one-home tax exemption is the core of capital gains tax savings. As of 2025, three requirements must be met: transfer price of 1.2 billion won or less, holding period of 2+ years, and residence period of 2+ years. Meeting these requirements means paying zero tax regardless of whether capital gains are 1 billion or 2 billion won.

The 2-year holding period is calculated from acquisition date to transfer date. For example, a home acquired on March 1, 2023 must be transferred after March 1, 2025 to meet the 2-year requirement. Even one day short disqualifies for exemption, making precise date calculation important.

The 2-year residence period means actually living in the property. Resident registration must be filed, and actual residence can be verified through electricity and gas usage records. Renting out the property while living elsewhere may not qualify as residence period.

The 1.2 billion won threshold is based on actual transfer price, not capital gains. If selling for 1.25 billion won, capital gains tax applies to the entire amount. Therefore, homes near 1.2 billion won require careful pricing decisions.

Temporary 2-home status can also qualify for exemption. When acquiring a new home while owning an existing one, selling the old home within 3 years (2 years for adjustment areas) can maintain tax exemption. Valid reasons include relocation, job transfer, or family care, and you must move into the new home within 1 year of acquisition.

Long-term holding deductions provide tax benefits to taxpayers who hold real estate for extended periods. As of 2025, 3+ years of holding starts at 12%, increasing to 16% for 4 years, 20% for 5 years, 24% for 6 years, 28% for 7 years, 32% for 8 years, 36% for 9 years, 40% for 10 years, and up to 50% for 15+ years.

For example, with capital gains of 200 million won held for 10 years, 40% or 80 million won is deducted, reducing the tax base to 120 million won. This saves tens of millions in taxes. Holding for 15+ years deducts 100 million won, further reducing the tax base to 100 million won.

One-home households receive additional deductions based on residence period. For 2+ years of residence, residence period deductions are added to basic deduction rates: 2+ years 8%, 3+ years 12%, 4+ years 16%, increasing to 30% for 10+ years. Combined holding and residence deductions can reach up to 80%.

To maximize long-term holding deductions, strategically time property sales. If holding period is 2 years 11 months, waiting one more month to reach 3 years is advantageous. At 9 years 11 months, holding one more month to apply the 10-year deduction rate of 40% is beneficial.

However, multiple home owners in adjustment target areas are excluded from long-term holding deductions. Owners of 2+ homes transferring property in adjustment areas cannot receive long-term holding deductions and face heavier taxation. Therefore, multiple home owners need strategies to reduce home count.

As of 2025, heavy taxation on multiple home owners remains in effect. Owners of 2 homes in adjustment target areas have 20 percentage points added to the basic rate, and 3+ home owners have 30 percentage points added. With maximum rates reaching 75%, most capital gains may go to taxes.

The first way to avoid heavy taxation is selling homes in non-adjustment areas first. Homes in non-adjustment areas are not subject to heavy taxation, so reducing home count by disposing of non-adjustment properties before selling adjustment area homes is an effective strategy.

Utilizing temporary 2-home special provisions is also beneficial. Even when acquiring a new home while owning an existing one, selling the old home within a certain period qualifies as temporary 2-home status, avoiding heavy taxation. Adjustment areas require 2 years, non-adjustment areas 3 years.

Joint marital ownership is another approach. When spouses each own 1 home in non-adjustment areas, each can apply one-home exemption. However, in adjustment areas, home counts are combined for married couples, requiring caution.

Inherited homes are excluded from home counts for a certain period. Selling inherited homes within 5 years calculates taxes separately from regular homes, avoiding heavy taxation. Therefore, selling inherited homes within 5 years is tax-advantageous.

Pre-sale rights and occupancy rights may also count as homes. Pre-sale rights in adjustment target areas are treated as homes, affecting multiple home determination. Careful planning is needed when holding pre-sale rights alongside existing homes.

One of the most effective ways to reduce capital gains tax is maximizing necessary expense deductions. Necessary expenses include acquisition tax, brokerage fees, legal fees, and renovation costs. Properly documenting these expenses reduces capital gains and significantly cuts taxes.

Acquisition tax paid when purchasing property is a typical deductible necessary expense. Acquisition tax on a 300 million won home is approximately 9 million won, and recognizing this as necessary expense reduces capital gains by that amount. Acquisition tax payment receipts must be kept.

Brokerage fees are also recognized as necessary expenses. Fees paid during real estate transactions are included as necessary expenses for both acquisition and transfer. Brokerage fees for a 500 million won home typically range 0.4-0.5%, about 2-2.5 million won, and occur for both purchase and sale, totaling 4-5 million won in deductions.

Renovation costs can qualify as capital expenditures. Not simple repairs but improvements increasing property value (adding rooms, expanding bathrooms, replacing heating systems) are recognized as necessary expenses. Documentation through tax invoices, estimates, and photos is required, with bank transfers or card payments preferred over cash.

Eviction costs, moving expenses, and loan interest may also qualify as necessary expenses. Receipts for tenant eviction costs, legal fees, registration fees, etc. must be kept for filing. Loan interest can qualify under certain conditions.

Documentation is essential for necessary expense recognition. Contracts, receipts, tax invoices, and bank statements must be systematically maintained. Cash payments are difficult to recognize, so bank transfers or card payments with documentation are necessary.

Capital gains tax must be filed and paid within 2 months from the end of the month of property transfer. For example, if final payment was received on March 15, 2025, filing is due by May 31. The earlier of final payment date or ownership transfer date is the basis, not registration date.

Filing can be done by visiting the local tax office or electronically through Hometax. Hometax electronic filing is available 24/7, and required documents can be scanned and attached. For complex cases, seeking professional tax advice is recommended, with fees typically 300,000-1,000,000 won.

Documents required for filing include capital gains tax return, capital gains calculation statement, copies of acquisition and transfer contracts, acquisition tax receipts, property register, and necessary expense documentation. For one-home exemption, resident registration and household entry records are also needed.

Failure to file on time results in non-filing penalties. 20% of calculated tax is added, rising to 40% for fraudulent non-filing. Additionally, late payment penalties of 0.022% per day apply. Delaying 100 million won in tax by one year incurs approximately 8 million won in penalties.

Understanding preliminary and final filing differences is important. Filing within 2 months from month-end of transfer is preliminary filing, which also serves as final filing. Separate final filing is unnecessary, but if additional necessary expenses are found or calculation errors exist, correction requests can be made.

Installment payment systems are also available. When tax due exceeds 10 million won, 10 million won is paid immediately and the remainder can be paid in installments within 2 months. For amounts exceeding 20 million won, installment periods extend up to 45 days.

When transferring real estate acquired through inheritance or gift, different rules apply than regular purchases. The biggest difference is acquisition price calculation method. For inherited or gifted property, acquisition price is not the market value at time of inheritance or gift, but succeeds the original acquisition price and date of the deceased or donor.

For example, if inheriting a home your father purchased for 100 million won in 2000, inheriting in 2020, and selling for 500 million won in 2025, capital gains are 500 million minus 100 million, equaling 400 million won. Even if 2020 inheritance value was 300 million won, acquisition price remains 100 million won.

Holding period also succeeds from the deceased. If your father held from 2000, long-term holding deductions calculate from 2000, not 2020 inheritance date. Calculating as 25 years of holding allows maximum 50% deduction.

One-home exemption can also succeed. If the deceased met one-home requirements, inheritors can succeed residence and holding periods for exemption application. However, if inheritors already own other homes, temporary 2-home requirements must be met.

Inherited homes sold within 5 years are excluded from home counts. Selling inherited homes within 5 years calculates capital gains tax separately from regular holdings, avoiding multiple home heavy taxation. Therefore, selling inherited homes within 5 years is tax-advantageous.

Gifted homes must consider both gift tax and capital gains tax. Gift tax is paid at gift time, and capital gains tax is paid again at transfer, creating double taxation burden. Therefore, inheritance or sale may be more advantageous than gifting, requiring professional tax consultation.

Let us examine capital gains tax calculation through an actual case. Mr. A purchased a Gangnam-gu apartment for 500 million won in March 2020 and sold it for 800 million won in June 2025, with 5 years holding period, 5 years residence, and one-home household status.

First, verify one-home exemption requirements. Holding period 2+ years and residence period 2+ years are met, but transfer price exceeds 1.2 billion won requirement, disqualifying for exemption. Therefore, regular capital gains tax applies.

Capital gains are 800 million minus 500 million, equaling 300 million won. Subtracting necessary expenses of 24.2 million won (acquisition tax 14 million, purchase brokerage 2 million, sale brokerage 3.2 million, renovation 5 million), actual capital gains are 275.8 million won.

Apply long-term holding deduction. 5-year holding qualifies for 20% deduction, so 275.8 million × 20% = 55.16 million won is deducted. Therefore, tax base is 220.64 million won.

Calculate capital gains tax. Up to 14 million at 6% = 840,000 won, 14-50 million at 15% = 5.4 million won, 50-88 million at 24% = 9.12 million won, 88-150 million at 35% = 21.7 million won, 150-220.64 million at 38% = 26.84 million won, totaling 63.9 million won.

Adding 10% local income tax, final payment is 63.9 million × 1.1 = 70.29 million won. Mr. A received 800 million but actual net profit is 800 million - 500 million (acquisition) - 70.29 million (tax) - 24.2 million (expenses) = approximately 205.51 million won.

If Mr. A had sold below 1.2 billion won, exemption would save 70 million won in taxes. When selling price is near 1.2 billion won, price adjustments can provide significant tax benefits.

First, maximize one-home exemption benefits. Meeting 1.2 billion won or less, 2-year holding, 2-year residence requirements can save tens of millions in taxes. Adjusting sale timing to meet holding and residence periods is crucial.

Second, adjust sale timing for long-term holding deductions. If holding period is 2 years 11 months, waiting one month to reach 3 years earns 12% deduction. Especially at 9 years 11 months, holding one more month for 10-year deduction of 40% is advantageous.

Third, collect all necessary expenses. Keep receipts for acquisition tax, brokerage fees, legal fees, renovation costs, and document with bank transfers or card payments. Cash transactions are difficult to recognize as necessary expenses.

Fourth, utilize temporary 2-home provisions. When purchasing new homes due to relocation or job transfer, selling old homes within certain periods maintains exemption. Adjustment areas require 2 years, non-adjustment areas 3 years.

Fifth, strategically use joint marital ownership. Spouses each owning 1 home can each apply exemption in non-adjustment areas. However, carefully consider gift tax and acquisition tax.

Sixth, sell inherited homes within 5 years. Selling inherited homes within 5 years calculates separately from regular homes, avoiding heavy taxation. Especially for multiple home owners, disposing inherited homes first is advantageous.

Seventh, sell non-adjustment area homes first. Multiple home owners transferring adjustment area properties face heavy taxation, so disposing non-adjustment properties first to reduce home counts is beneficial.

Eighth, be cautious with pre-sale and occupancy rights. Pre-sale rights in adjustment areas count as homes, affecting multiple home determination. If planning to sell existing homes, carefully consider pre-sale right acquisition.

Ninth, seek professional tax advice. Understanding complex tax laws and various deduction systems is difficult. For tax amounts in tens of millions, professional fees of 300,000-1,000,000 won are worthwhile investments.

Tenth, strictly observe filing deadlines. Non-filing penalties of 20% and late payment penalties can be as burdensome as the principal tax. File and pay within 2 months from month-end of transfer date.