How this calculator works
Cost basis is shares × purchase price plus the buy commission; proceeds are shares × sale price minus the sell commission. Return is profit divided by cost. Annualized return scales that to a 365-day year based on how long you held the shares.
Worked example
With the example values below: Profit, $2,200 (44.00% return). Change any number above to run your own.
What you enter
| Input | Example |
|---|---|
| Shares | 100 |
| Purchase price / share | $50 |
| Sale price / share | $72 |
| Buy commission | $0 |
| Sell commission | $0 |
| Days held | 540 |
Gain, return and annualized return
Profit is what you received from the sale minus what you paid, including commissions. Return is that profit as a percentage of your cost. Annualized return converts it to a yearly rate, so a quick trade and a long hold can be compared fairly.
Buy 100 shares at $50 and sell at $65 after 18 months: profit is $1,500, return is 30%, and the annualized return is about 19% a year.
Cost basis
Cost basis is what you paid for shares, including fees. It's what taxes are based on. If you bought shares at different prices, your broker usually sells the oldest shares first (first in, first out) unless you choose specific lots. Selling high-cost lots first can lower taxable gains.
Reinvested dividends add to your cost basis, and stock splits change the per-share basis without changing the total.
Taxes on stock gains
The capital gains tax calculator estimates the tax on your profit.
- Held one year or less: short-term gain, taxed at ordinary income rates.
- Held more than one year: long-term gain, taxed at 0%, 15% or 20% in 2026.
- Losses offset gains, and up to $3,000 of net losses a year can offset ordinary income.
- Buying the same stock within 30 days before or after selling at a loss triggers the wash-sale rule, which defers the loss.
Frequently asked questions
How do you calculate stock profit?
Multiply the shares by the sale price and subtract the sell commission, then subtract what you paid: shares × purchase price plus the buy commission. Buying 100 shares at $50 and selling at $65 with no commissions is a $1,500 profit, a 30% return.
How much tax do you pay on stock profits?
Shares held one year or less are short-term gains, taxed at your ordinary income rate. Shares held longer are long-term gains, taxed at 0%, 15% or 20% in 2026 depending on your taxable income. Higher earners may also owe the 3.8% net investment income tax.
What is annualized return?
Your return scaled to a one-year period, so trades held for different lengths of time can be compared. A 10% gain in six months is roughly a 21% annualized return; the same 10% over two years is about 4.9% a year.
How do I calculate percentage gain on a stock?
Subtract your total cost from your sale proceeds, divide by your total cost and multiply by 100. Buying at $40 and selling at $52 is a 30% gain before commissions.
If a stock goes up 100%, how much do you make?
You double your money: $5,000 becomes $10,000, a $5,000 profit before commissions and taxes. It doesn't work the same way down. A stock that falls 50% has to rise 100% just to get back to where it started.
What is a wash sale?
Selling a stock at a loss and buying the same or a substantially identical security within 30 days before or after. The loss is disallowed for now and added to the cost basis of the new shares.
Grow what this calculator projects.
TruthSayer AI sends quantitative stock signals across valuations, earnings and dark-pool activity, each one traded in its own funded account first.
Estimates for planning only, not financial, tax or legal advice. Tax tools use 2026 federal figures (brackets, $16,100 / $32,200 standard deduction, $19,000 gift exclusion, $15M lifetime exemption). Rates shown as defaults are examples; replace them with quotes you actually receive.