Stock ROI Calculator
Last updated: 2026-06-25
Stock ROI (%) is net profit/loss divided by the total buy amount. Net P/L = sell amount − buy amount − buy/sell fees − securities transaction tax.
General Korean investors (excluding major shareholders) are exempt from capital gains tax and pay only the 0.18% securities transaction tax on selling.
Enter trade details
After-tax return
0%
| Item | Amount |
|---|---|
| Total buy amount | |
| Total sell amount | |
| Buy fee | |
| Sell fee | |
| Securities transaction tax | |
| After-tax net P/L |
General Korean investors (excluding major shareholders) are exempt from capital gains tax, so it is not included here. Results are estimates for reference only; check your broker statement for exact costs.
How to use
- Enter trade details — enter the buy price, sell price and shares held. You can find your average cost with the Average Cost Calculator.
- Enter fees and tax — confirm the one-way trading fee rate and the securities transaction tax (default 0.18%), or edit them to your account.
- View results — press "Calculate ROI" to see the after-tax net profit/loss and return (%) line by line.
How to calculate stock ROI and tax
Your realized return on a trade is not simply (sell price − buy price) ÷ buy price. In reality, buy/sell fees and the sell-side securities transaction tax are deducted, so your realized return is slightly lower than the displayed return. Net P/L is computed as follows.
Net P/L = sell amount − buy amount − buy fee − sell fee − securities transaction tax, ROI = net P/L ÷ buy amount × 100
| Item | Basis | When charged |
|---|---|---|
| Securities transaction tax | Sell amount × 0.18% | On selling |
| Brokerage fee | About 0.01%–0.5% (by broker) | On buying & selling |
| Capital gains tax (retail) | Exempt (excluding major shareholders) | N/A |
| Dividend tax | 15.4% (on dividends) | On dividend payout |
For Korean listed stocks, ordinary minority shareholders' trading gains are not subject to capital gains tax. So on selling you incur only the 0.18% securities transaction tax plus two-way fees. If you receive dividends, the separate 15.4% dividend tax applies, which you can check in the Dividend Calculator. For more detail, see the Stock ROI & Tax Basics guide.
Frequently asked questions (FAQ)
How is stock ROI calculated?
Stock ROI (%) is net profit/loss divided by the total buy amount. Net P/L = sell amount − buy amount − buy fee − sell fee − securities transaction tax, and ROI = net P/L ÷ buy amount × 100. This calculator shows the realized return after fees and tax.
How much is the securities transaction tax in Korea?
As of 2025, the securities transaction tax on Korean listed stocks is 0.18% of the sell amount (KOSPI including the special rural tax basis; KOSDAQ 0.18%). It applies only when selling, not when buying. The rate has been reduced in steps and may change.
Do retail investors pay capital gains tax on Korean stocks?
For Korean listed stocks, ordinary minority (non-major) shareholders are exempt from capital gains tax. So general investors pay only the securities transaction tax on trading gains. Major shareholders are subject to capital gains tax, and overseas stocks are taxed separately (22% after a 2.5 million KRW annual deduction).
What is a typical trading fee rate?
Broker brokerage fees are usually around 0.01%–0.5%, and may be very low or free with non-face-to-face accounts or promotions. Enter your account's actual fee rate for a more accurate net P/L.
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Last updated: 2026-06-25