Stock Average Calculator
Add each purchase (price and quantity) to find your average buy price and total investment.
About the Stock Average Calculator
The Stock Average Calculator finds your average buy price when you purchase the same stock several times at different prices and quantities. Add each purchase and see the weighted average cost per share and the total invested.
The average price is the total money spent divided by the total number of shares, not the simple average of the prices. If you buy 10 shares at 100 and 30 shares at 80, the average is (1000 + 2400) / 40 = 85, not 90. Knowing this number tells you at what price you break even, before fees and taxes. "Averaging down" means buying more as the price falls, which lowers your average cost but also increases your exposure to the stock.
How to use it
- Enter the price and quantity of your first purchase.
- Press + Add another purchase for each additional buy.
- Read the average price and total quantity.
- Compare with the current price to see profit or loss.
Tips and good to know
- Include brokerage fees by adding them to the price per share.
- Averaging down does not guarantee recovery; only add to positions you still believe in.
- Keep records of every purchase for tax reporting.
Frequently asked questions
Why isn't it the simple mean of prices?
Larger purchases carry more weight.
Does it include brokerage?
Not unless you add it to the price.
Is this investment advice?
No, it is arithmetic only.