How to use
- Enter the number of shares you currently hold and your existing average cost.
- Enter the number of shares you plan to buy and the new buy price.
- Read the updated average cost, total shares, and total invested amount instantly.
Examples
- Holding 10 shares at $100 and buying 10 more at $80 gives a new average cost of $90 across 20 total shares ($1,800 invested).
- Holding 50 shares at $200 and adding 25 at $150 recalculates to $183.33 average — all in your browser, nothing is stored or sent anywhere.