Free Financial Tool · Any Currency

Target Average Price Calculator

Figure out exactly how many more shares you need to buy, at a given price, to bring your average cost down (or up) to a specific target.

Open CalculatorHow it works

    Your Position

    What you already own, the price you're considering buying at, and the average you want to reach.

    $
    $
    $
    Shares you need to buy
    0

    Fill in all four fields on the left to see your result.

    After This Purchase
    New total shares
    N/A
    New total invested
    N/A
    Resulting average price
    N/A
    Getting Started

    What Does a Target Average Price Calculator Do?

    If you already own shares of a stock, you can work out exactly how many more shares you'd need to buy, at a specific price, to move your average cost to a specific target. This is the reverse of the usual calculation: instead of "what's my average after these purchases," it answers "how many shares do I need to buy to reach the average I want."

    It only works for a target that's mathematically reachable. If you're averaging down, your target has to sit between the new purchase price and your current average. No number of shares can pull your average below the price you're actually paying.

    The Math

    The Target Average Formula

    Starting from the weighted average formula and solving for the number of new shares gives a direct answer, rather than requiring trial and error.

    Shares Needed = Current Shares × (Target Average − Current Average) ÷ (New Price − Target Average)

New Total Shares    = Current Shares + Shares Needed
New Total Invested  = (Current Shares × Current Average) + (Shares Needed × New Price)
Resulting Average   = New Total Invested ÷ New Total Shares

    The "Resulting Average" line is just a check: plug the calculated share count back into the ordinary weighted average formula and it should land exactly on your target. That's how this calculator verifies its own answer every time you use it.

    Worked Example

    Real Numbers, Step by Step

    Bringing a $90 Average Down to $80

    You own 200 shares at a $90.00 average price. The stock has dropped to $70, and you want to know how many shares to buy at $70 to bring your average down to exactly $80.

    Before
    Shares
    200
    Average price
    $90.00
    Total invested
    $18,000
    After Buying 200 More at $70
    Shares
    400
    Average price
    $80.00
    Total invested
    $32,000

    Shares needed = 200 × (80 − 90) ÷ (70 − 80) = 200

    You'd need to buy exactly 200 more shares at $70 to land your average precisely on $80. Buying fewer would leave your average above $80; buying more would push it below $80.

    Related Tools

    Already know your purchases and just want your current average? Use the Stock Average Calculator. Investing a fixed amount on a schedule instead of a one-off purchase? Try the Dollar-Cost Averaging Calculator. Deciding whether averaging down makes sense in the first place, rather than just doing the math? The averaging down vs. up strategy guide covers when it's a reasonable decision and when it's a value trap.

    Questions

    Frequently Asked Questions

    How many shares do I need to buy to lower my average?

    It depends on your current shares, current average, the new purchase price, and the target you want to hit. This calculator solves that directly: Shares Needed = Current Shares × (Target − Current Average) ÷ (New Price − Target).

    Can I reach any target average I want?

    No. If you're averaging down, your target has to be somewhere between the new purchase price and your current average, not below the new price itself. No amount of buying can pull your average below what you're actually paying per share.

    What if the calculator says my target is impossible?

    That means the target you entered is outside the achievable range given your current average and the new purchase price. The calculator explains why and shows you the actual range your target needs to fall within.

    Does a lower average mean lower risk?

    No. Lowering your average price reduces the price needed to break even, but it increases your total dollars invested in that position. If the price keeps falling, you have more money exposed to further losses, not less.

    Can I use this to average up instead of down?

    Yes. If the new purchase price is above your current average, enter a target between your current average and the new price, and the calculator solves the same way.