Average Down Calculator

Averaging down means buying more shares of a stock you already own after its price falls. The new shares cost less than your earlier ones, so your average cost per share drops. Averaging up is the same math after a rise: buying at a higher price lifts your average, so this also works as an average up calculator.

Either way the position grows. A lower average means the stock needs a smaller rise for you to break even, but more of your money now rides on the same stock, which raises your risk if it keeps falling. This stock average calculator, also called a share average calculator, shows the math of each buy. It is not a signal to buy or sell.

To calculate the average cost of a stock after multiple purchases, multiply each purchase price by its number of shares, add up the totals and divide by the total number of shares you own. It is a weighted average, so a buy of 50 shares moves it more than a buy of 10, and your average stock price sits closer to the price of your larger buys.

Enter a fee per trade and the calculator adds it to every purchase, so your average cost includes what you paid to buy. Break-even adds one more fee for the sale. With no fees, your break-even price equals your average cost.

• Total invested = shares x price for each purchase, added up, plus any fees
• Average cost per share = total invested / shares owned
• Break-even price = (total invested + one more fee for the sale) / shares owned

Say you bought 50 shares at $80.00, then 30 more at $72.00 and 20 more at $65.00 as the price fell. You paid $7,460.00 for 100 shares, an average cost of $74.60 a share, and with no trading fees your break-even price is also $74.60.

At $60.00 the position is down $1,460.00 (19.57%), so the price needs to rise 24.33% to get back to break-even. Buying 50 more shares at $60.00 costs $3,000.00 and lowers your average cost by $4.87, to $69.73.

To bring your average cost to $70.00 instead, you would buy 46 shares at $60.00, about $2,760.00. A target of $55.00 is out of reach at that price, because buying at $60.00 can only pull your average toward $60.00. Any target has to sit between $60.00 and $74.60.

With no fees, the number of shares to buy to reach a target average is shares owned x (average cost - target) / (target - buy price). With a fee per trade, the calculator also counts the fee on that purchase.

A target only works when it sits between the price you would pay and your current average. Each new share pulls the average toward the buy price but never all the way there, so you cannot average down to the current price while you hold shares bought higher. When the answer is part of a share, the calculator also shows the whole number of shares and the average they give.

Your average cost basis is the average cost per share shown here. Multiplied by your shares, it gives your total cost basis, the amount a gain or loss is measured from. The Total invested row shows that total, so the page also works as a simple stock cost basis calculator for one holding.

Brokers often track each purchase as a separate lot, and when you sell part of a position they may use first in, first out or another method to pick which shares you sold. Your tax form can then show a different gain than your average cost suggests. Break-even here ignores taxes, so use it for planning and check your broker's cost basis records for taxes. This page is not tax advice.