Stock Average Calculator
Calculate your new average share price after buying more of the same stock.
"Averaging down" — buying more of a stock after it falls — lowers your average cost per share and therefore your break-even price. Whether that's a smart move or throwing good money after bad is a judgment call, but either way you should know exactly what your new average is before you place the order.
Enter the shares and price for your existing position and for the new purchase, and this calculator returns the weighted average price, total share count, and total invested. It works equally well for averaging up in a rising stock or consolidating two separate buys for tax records.
How to use Stock Average Calculator
- 1
Enter your first purchase
Number of shares and the price you paid per share.
- 2
Enter your second purchase
The new buy — shares and price.
- 3
Read your new average
Weighted average price, total shares and total cost.
Features
- Weighted average across two purchases
- Shows total position size and invested amount
- Works for averaging down or up
Frequently asked questions
Common mistakes to avoid
- Averaging the two prices directly ((p1+p2)/2) without weighting by share count.
- Forgetting brokerage fees and taxes, which raise the true break-even slightly above the average price.
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