Stock Profit Calculator
Sold a stock and want to know what you really made? Enter your buy price, sell price, and shares to see net profit, return %, and break-even in seconds — then add buy/sell fees, transaction tax, and capital gains tax for the after-tax number. Works in any currency.
Fees & tax (optional)
Country preset (fills tax fields — editable)
Full breakdown
Some values were above the allowed range and were capped for this calculation.
This is an arithmetic calculation, not investment advice.
Every calculation runs in your browser — nothing is sent to a server.
Frequently asked questions
What does "net profit" mean and what is the exact formula?
Net profit is what you actually keep after a round-trip trade: your sell proceeds minus every cost. This stock profit calculator works it out in steps — buy cost is your buy price × quantity × (1 + buy fee); sell proceeds are sell price × quantity, minus the sell fee and any transaction tax; the difference is your pre-tax gain. If that gain is positive, capital gains tax is applied to it (after any basic deduction), and net profit = pre-tax gain − capital gains tax. Return % is net profit ÷ buy cost × 100.
How is the break-even sell price computed, and why do fees and transaction tax raise it but capital gains tax doesn't?
The break-even sell price is the price at which your proceeds after selling costs exactly cover your buy cost. This break even sell price calculator divides your total buy cost (buy fee included) by quantity × (1 − sell fee − transaction tax). Sell fees and transaction tax are money you never get back, so they push the break-even above your buy price. Capital gains tax does not raise break-even: tax only applies when there is a gain, and at break-even the gain is exactly zero, so there is nothing to tax.
What do the Korea and US tax presets use?
The presets fill the tax fields so you don't have to look them up, and every value stays editable. Korea domestic uses an approximate 0.20% securities transaction tax (KOSPI, special rural tax included; base year 2026, per Korea's Securities Transaction Tax Act) and 0% capital gains tax, since small shareholders of listed Korean shares are exempt. Korea overseas — the 주식 양도세 계산기 case — uses 22% capital gains tax (20% plus 2% local surtax) with a 2,500,000 KRW annual basic deduction. US uses a 15% long-term capital gains rate as a representative figure. Rates change and depend on your broker, exchange and situation, so treat the presets as a starting point and edit them.
Why is this a simplified estimate, and how do I use my own rate?
This capital gains tax calculator applies a single flat rate to your whole gain after one basic deduction. Real tax can be more involved: progressive brackets, short vs long holding periods, the US 0/15/20% tiers plus the 3.8% net investment income tax, and loss carry-forward or offsetting against other trades. None of that is modelled here. If your rate differs, just type your own capital gains rate and deduction into the advanced fields and the after-tax number updates instantly.
Does it work in any currency, and is anything sent to a server?
The math is currency-agnostic: pick any currency and amounts follow your locale's symbol, grouping and decimals (KRW and JPY show no decimals, USD and EUR show two) — nothing is hard-coded. Quantities accept up to four decimals, so fractional shares work like whole ones. Nothing is sent to a server and no prices are fetched from any market feed — you type every price yourself, and your last entry is saved only in your browser. This 주식 수익 계산기 is arithmetic, not investment or tax advice.