Stock average cost calculator
Averaging down changes your break-even price. This is the arithmetic behind that.
Average cost per share
41.0000
- Total shares
- 250.0000
- Total invested
- 10 250.00
- Current value
- 10 000.00
- Unrealised profit or loss
- -250.00
- Return
- -2.439 %
Show the working
- First purchase, shares = 100
- First purchase, price = 50
- Second purchase, shares = 150
- Second purchase, price = 35
- Current price = 40
- Total shares = 100 + 150 = 250
- Total invested = 100*50 + 150*35 = 10 250
- Average cost per share = 250 > 0 ? 10 250 / 250 : 0 = 41
- Current value = 250 * 40 = 10 000
- Unrealised profit or loss = 10 000 - 10 250 = -250
- Return = 10 250 > 0 ? -250 / 10 250 * 100 : 0 = -2.439 02
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
Scenarios & local history
Compare a saved scenario
Recent calculations
The formula
- average cost = total spent / total shares
Averaging down lowers your break-even but raises your exposure to a position that is already losing.
This is arithmetic, not financial advice. Real products carry fees, tax treatment and terms that no formula captures.