Stock Average Down Calculator
Blend up to four buy lots into one average cost per share, then see your break-even price and unrealized gain or loss.
How it works
Average cost = total cost ÷ total shares · Break-even = average cost · Unrealized = shares × current price − total cost
Averaging down means buying more shares at a lower price to pull your overall cost per share down. The blended average is simply every dollar you have invested divided by every share you own, which is also the break-even price — sell above it and you are ahead, below it and you are behind. A lower average makes break-even easier to reach, but it also puts more money into a position that has already fallen, so it raises your total risk if the decline continues.
Worked example
Buying 100 shares at $50 ($5,000) and then 50 more at $40 ($2,000) gives 150 shares for $7,000 — an average of about $46.67 each. With the price now at $45, the position is worth $6,750, an unrealized loss of about $250, and you break even once the price climbs back to $46.67.
Frequently asked questions
Is averaging down a good idea?
It lowers your break-even, but only pays off if the price recovers. Adding to a position that keeps falling — sometimes called catching a falling knife — deepens the loss. The decision should rest on why the price dropped, not on the average alone.
Does this include commissions?
No. Commissions raise your real cost basis and nudge break-even slightly higher. Fold any per-trade fees into each lot price for a closer figure.
What is the difference from dollar-cost averaging?
Dollar-cost averaging is buying on a fixed schedule regardless of price. Averaging down is deliberately buying more after a drop. Both lower your average cost, but the intent and the risk are different.
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Educational estimate, not investment or tax advice. Returns are never guaranteed and past performance does not predict the future. Confirm with a licensed advisor.