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Average Cost & Break-Even Calculator

Find your real cost basis after buying in pieces. Enter each lot's shares and price to get your blended average cost — the break-even price the whole position needs to reach.

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  • Calculated in your browser, not on our servers
  • Formula shown with your numbers

Your lots

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Average cost / break-even

Average cost (your break-even)
$47.50
200 shares across 2 lots
Total shares200
Total cost$9,500.00
The math

$9,500.00 ÷ 200 shares = $47.50

Averaging down lowers the break-even and adds capital to a losing position. Decide your stop before you add.

For education and planning. Results are estimates that leave out taxes and may leave out fees and slippage. Not investment advice. Check the numbers against your broker before you trade.

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How it works

When you buy a stock in more than one lot — or average down after a drop — your break-even isn't your first price; it's the share-weighted average of every lot. Average cost = total dollars spent ÷ total shares. That blended number is the price at which the combined position is flat.

Averaging down lowers your break-even but also adds risk: you're committing more capital to a position that's already moving against you. It works when your thesis is intact and you've planned the adds in advance; it hurts when it's a reflex to a losing trade with no stop. Size the adds, and know the level that would prove you wrong.

StockSetups attaches a stop and target to every setup, so you can decide ahead of time whether a name is worth adding to — or whether the stop says it's time to step aside.

Frequently asked

How do you calculate average cost?

Average cost = total amount spent ÷ total shares owned. Multiply each lot's shares by its price, add those up, and divide by the total shares. The result is your blended cost basis and break-even price.

What is averaging down?

Buying more of a stock at a lower price than your initial entry, which lowers your average cost. It reduces your break-even but increases the capital and risk committed to a losing position — best done with a plan and a stop, not as a reflex.

Is my break-even the same as my average cost?

Yes — ignoring commissions and fees, your break-even price equals your average cost. Reach that price and the position is flat.

Use it with

Position Size CalculatorAccount, risk and your stop → the exact share count, long or short.Risk/Reward CalculatorEntry, stop and target → reward:risk, break-even win rate and expectancy.

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