How to Use Stock Calculator
The Stock Calculator gives you a complete picture of your stock investment performance in seconds.
- Buy Price — Enter the price per share you paid when purchasing the stock.
- Current Price — Enter the current or target price per share.
- Number of Shares — Enter how many shares you hold.
- Buy Commission — Optionally enter the fee you paid when buying (leave as 0 if none).
- Sell Commission — Optionally enter the expected fee when selling. The Stock Calculator deducts this from your net profit.
The Stock Calculator instantly displays total cost, current market value, net profit/loss, and return rate. Positive figures are highlighted in green; negative figures appear in red for quick visual reference.
Formula & Theory — Stock Calculator
The Stock Calculator applies four straightforward formulas:
Total Cost = Buy Price × Shares + Buy Fee
Current Value = Current Price × Shares
Net Profit / Loss = Current Value − Total Cost − Sell Fee
Return Rate (%) = Net Profit / Loss ÷ Total Cost × 100
| Symbol | Meaning |
|---|---|
| Buy Price | Price paid per share at time of purchase |
| Current Price | Current or hypothetical future price per share |
| Shares | Total number of shares held |
| Buy Fee | Commission or transaction cost paid when buying |
| Sell Fee | Commission or transaction cost expected when selling |
Including fees in the Stock Calculator is especially important for smaller positions, where fees can represent a significant portion of the return.
Break-Even Price
To find the break-even price (the price at which you would neither gain nor lose after fees), rearrange the formula:
Break-Even Price = (Total Cost + Sell Fee) ÷ Shares
You can quickly estimate this by entering your numbers and finding the current price at which Net P/L equals zero.
Use Cases for Stock Calculator
The Stock Calculator supports a wide range of investment decisions and analyses:
- Performance tracking — Monitor the current profitability of individual stock positions in your portfolio using the Stock Calculator.
- Target price planning — Enter a target price to see the potential profit or return rate if the stock reaches that level.
- Fee impact analysis — Compare scenarios with and without commissions to understand the true cost of trading.
- Stop-loss and take-profit reference — Use the Stock Calculator to find the price levels corresponding to specific loss or gain thresholds.
- Tax preparation — Quickly determine realized gains or losses on closed positions for reporting purposes.
The Stock Calculator is designed for individual equities, but the same logic applies to ETFs, REITs, and other exchange-traded instruments priced per share.