Learning how to calculate average price of shares is one of the first skills every stock investor needs, because most people do not buy all their shares in a single trade. You might buy a few shares one month, add more when the price falls, and add again later at a higher price. The average price tells you, in one number, what each share has effectively cost you across all those purchases. To check your own holdings quickly, try our free Groww Average Calculator.
That single number matters because it is the break-even point for your position. If the market price is above your average, your holding is in profit before charges; if it is below, you are still waiting to recover your cost. It also stops a common error: taking a simple average of the prices you paid, which ignores how many shares you bought at each price.
The Method / Formula
The formula is simple once you think in totals rather than prices: Average price = Total amount invested / Total number of shares. Each part has a clear meaning. Total amount invested is the sum of what you paid in every purchase, and total number of shares is the sum of the shares bought in every purchase.
Work out each purchase separately first. For one purchase, multiply the number of shares by the price per share to get its cost. Add those costs together for the total invested, add the share counts together for the total shares, and then divide the first total by the second. The result is a weighted average: a purchase of more shares pulls the average more strongly towards its price than a small purchase does.
How to Calculate Average Price of Shares Step by Step
- List every purchase of the same share, with the number of shares and the price paid for each lot.
- Multiply shares by price for each lot to find what each purchase cost.
- Add all the purchase costs together to get the total amount invested.
- Add all the share counts together to get the total number of shares you now hold.
- Divide the total invested by the total shares. The result is your average price per share.
- Compare that average with the current market price to see whether the holding is above or below its break-even level.
Keep bonus shares and splits in mind if they apply: they change the share count without a new cash purchase, so they will change the average too. For a straightforward series of cash buys, however, the steps above are all you need.
Worked Example
Suppose you bought shares in three lots: 10 shares at Rs 100, 20 shares at Rs 90, and 10 shares at Rs 110. First, work out each lot: 10 x Rs 100 = Rs 1,000; 20 x Rs 90 = Rs 1,800; and 10 x Rs 110 = Rs 1,100.
Now add the totals. The total invested is Rs 1,000 + Rs 1,800 + Rs 1,100 = Rs 3,900, and the total shares are 10 + 20 + 10 = 40. Divide Rs 3,900 by 40 to get an average price of Rs 97.50 per share.
Compare that with a simple average of the three prices, which would be Rs 100. That figure treats each price equally and ignores how many shares were bought at each one. The weighted figure, Rs 97.50, is the correct cost per share because the cheaper Rs 90 lot was the largest, with 20 shares. That is why the number of shares in each lot always matters.
Common Mistakes / Good to Know
- Taking a simple average of prices: always weight each price by the number of shares bought at that price, or a small lot can distort the result.
- Forgetting brokerage and taxes: this calculation gives a pure price average, and brokerage, taxes and other charges are not included, so your true break-even price will be slightly higher.
- Thinking averaging down removes risk: buying more at a lower price lowers the average, but it also increases the total amount invested in that share, so it does not change total risk and can increase it if the price keeps falling.
- Mixing up shares from different companies: calculate the average separately for each stock, because prices and quantities from one company have nothing to do with another.
A lower average price feels reassuring, but it is only a record of what you have paid so far. Judge any further purchase on the company’s prospects and on how much of your portfolio it already represents, not on the average alone.
Frequently Asked Questions
What is the average price of shares?
It is the total amount you have invested in a share divided by the total number of shares you hold, so it shows your effective cost per share across all purchases.
Why is the average not a simple average of prices?
Because each price must be weighted by how many shares were bought at that price. A large purchase moves the average far more than a small one, so adding prices and dividing by the number of purchases gives the wrong cost per share.
Does averaging down reduce risk?
No. It lowers your average price, but it also puts more money into the same share. If the price keeps falling, your total loss can grow, so averaging down should be a deliberate decision, not an automatic habit.
Does the average include brokerage and taxes?
No, this is a pure price average. Brokerage, taxes and other charges are paid on top, so your true break-even price will be slightly higher than the average price shown.
Once you know your average price, the next question is how that holding performs over time. Use our XIRR Calculator to measure annualised returns, and read How to Calculate XIRR to understand what that return really means.