Stock Average Calculator

Averaging down means buying more shares of a stock you already own at a lower price to reduce your average cost per share. This calculator shows you exactly how additional purchases affect your cost basis, total investment, and potential profit or loss.

What is averaging down?

Averaging down (also called "buying the dip") is a strategy where you purchase additional shares of a stock after its price has declined. This lowers your average cost per share, meaning you need a smaller price increase to break even or turn a profit. However, it also increases your total exposure to the stock, so it's important to understand the risk.

How it works: If you bought 10 shares at $50 each ($500 total) and the price drops to $40, buying 10 more shares at $40 adds $400. Your new average cost is $900 / 20 = $45 per share — down from $50. The scenario table below shows how different buy prices affect your average.

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Stock Average Calculator — Cost Basis & Averaging Down

Free stock average calculator. Calculate cost basis, average down your stock positions, and see the impact of buying more shares at different prices.

New Average Cost$45.00
Total Shares20
Total Invested$900
Current Market Value$900
Total P/L+$0
P/L %+0.00%

Cost Basis Comparison

Scenario Table: Different Buy Prices

Buy PriceAdditional InvestmentTotal CostAvg CostMarket ValueP/LP/L %
$20.00$200$700$35.00$900+$200+28.57%
$30.00$300$800$40.00$900+$100+12.50%
$36.00$360$860$43.00$900+$40+4.65%
$40.00$400$900$45.00$900+$0+0.00%
$44.00$440$940$47.00$900-$40-4.26%
$50.00$500$1,000$50.00$900-$100-10.00%
$60.00$600$1,100$55.00$900-$200-18.18%

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