Stock Average Calculator
Average buy price across several purchases, with the position value.
Everything runs inside your browser. Your files never leave your device.
Input
Result
Ask about Stock Average Calculator
Questions about what this tool does, which option to pick, or what it can and cannot handle.
The question you type here is sent to an AI provider to be answered — your files and whatever you put in the tool above are not, and the assistant cannot see them. Answers are generated and can be wrong. The tool itself is not guessing: it runs deterministic code on your device.
About the Stock Average Calculator
Buy the same stock several times at different prices and your average cost is not the average of those prices — it is the total spent divided by the total shares. The distinction matters whenever the quantities differ, and it is where a quick mental sum usually goes wrong.
Buy ten shares at a thousand and ninety at a hundred, and the naive average of the two prices is five hundred and fifty. The real average cost is a hundred and ninety, because ninety per cent of the position was bought at the lower price. Weighting by quantity is the entire calculation, and doing it by eye reliably overstates the effect of the small trades.
Enter one purchase per line as a quantity and a price. The tool prints the weighted average, the total invested and a line for each purchase so you can check the entries. Add a current price and it also reports the value of the position and the profit or loss in both rupees and per cent.
A word on what averaging down actually does, since that is why most people arrive here. Buying more of a falling holding lowers the average cost, which makes the position look better on a statement without changing anything about the underlying business. The number moves whether or not the original decision was sound. Use the average price for what it is — the break-even level and the basis for a tax computation — rather than as evidence that the position is recovering.
For a portfolio built through many purchases over years, the more informative measure is XIRR, which weights by time as well as by amount.
How to use it
- 1Enter one purchase per line: the number of shares, a comma, then the price you paid.
- 2Run it to get the weighted average and the total invested.
- 3Add the current price to see the position value and the profit or loss.
- 4Use the average as your break-even level rather than as a verdict on the holding.
Questions
- Why isn't the average just the middle of my two prices?
- Because the quantities are almost never equal. A hundred shares at one price and ten at another are not two equal inputs, and weighting by quantity is the whole point of the calculation.
- Does averaging down actually help?
- It lowers your break-even price, which is arithmetic. Whether it is a good idea depends entirely on whether the holding is worth owning at the new price, which is a separate question the number cannot answer.
- Are brokerage and taxes included?
- No. Enter the price you paid per share; charges are worked out separately by the brokerage tool, which itemises every statutory line on a trade.
- Can I use this for units of a fund?
- Yes. Fractional quantities are accepted, so unit balances with decimals work exactly as share counts do.