Stock Profit Calculator

The calculator multiplies your pre-tax profit (gross proceeds minus cost basis) by the tax rate you enter, then subtracts the result to give after-tax net profit. The default rate is 15%, which matches the federal long-term rate for most US filers. Short-term gains (held one year or less) are taxed as ordinary income, so use your marginal rate instead. This is an estimate; your actual liability depends on your full tax picture.

A capital loss produces no tax owed on that trade. In reality you can use a loss to offset other gains or deduct up to $3,000 against ordinary income, but applying those rules requires your full-year tax picture. The calculator stays in scope: it sets tax to zero whenever pre-tax profit is zero or negative.

The break-even sell price is the per-share price at which your gross proceeds exactly equal your cost basis. The formula is (cost basis + sell commission) / shares. Selling above that price produces a profit; below it you take a loss.

The calculator computes both. Annualized return is arithmetic: it divides your after-tax ROI by the number of years held, so a 30% total return over 3 years shows as 10%/year regardless of compounding. CAGR is the steady annual rate that would grow your cost basis to the same after-tax ending value over the same period, accounting for compounding. For longer holds the gap between the two widens.

No. It models a single buy-and-sell of one position with no dividend income. If dividends matter for your trade, add the total dividends received to your sell-side proceeds before running the numbers, and note that qualified dividends carry their own tax rate separate from capital gains.