New average cost
Blends current holdings and the new purchase into a revised cost basis.
Investment calculator
Stock Yield Calculator — Average Down Cost Basis
Enter your current holdings and new purchase to calculate the new average cost, total invested, and unrealized P&L.
Stock Yield Calculator (incl. averaging down)
Current Holdings
New Purchase
Enter info and calculate
* Transaction fees and taxes are not included.
What is the stock yield calculator?
This tool combines your current shares, average cost, and a planned additional purchase to estimate the new average cost, total invested, market value, and unrealized P&L. Use it to understand how averaging down changes your break-even point before committing more capital.
How to use
- 1 Enter your current shares and average cost.
- 2 Enter the shares and price for the additional purchase.
- 3 Add the current price if you want market value and unrealized P&L.
- 4 Review fees, taxes, FX, dividends, and portfolio risk separately before deciding.
What it shows
Total invested
Shows the enlarged position size after the additional purchase.
Unrealized P&L
Uses the current price to estimate market value and percentage gain or loss.
FAQ
Does averaging down always reduce my loss?+
It can lower the average cost, but it also increases total capital at risk. If the stock keeps falling, the loss can grow.
Are fees and taxes included?+
No. The tool estimates cost basis and unrealized P&L only. Add brokerage fees, taxes, and FX separately.
Do I need to enter the current price?+
No. Without a current price, the tool is mainly for the new average cost; P&L output is limited.
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This is not investment advice. Actual returns can change with fees, taxes, FX, execution price, dividends, and market volatility.