What is a stock average calculator?
When you buy a share more than once at different prices, your cost per share becomes a weighted average of all the purchases. Knowing this average tells you the price the stock must reach for you to break even, and how much you gain or lose at today's price.
Average price formula
where Q is the quantity and P the price of each purchase.
Worked example
| Purchase | Quantity | Price | Cost |
|---|---|---|---|
| 1 | 100 | ₹500 | ₹50,000 |
| 2 | 100 | ₹400 | ₹40,000 |
| 3 | 200 | ₹350 | ₹70,000 |
| Total | 400 | ₹1,60,000 |
Average price = ₹1,60,000 ÷ 400 = ₹400. Note that it is not the simple average of the three prices (₹416.67), because more shares were bought at the lower price.
How to use it
- Enter the quantity and price of your first purchase.
- Add a row for every other purchase of the same stock (up to 20).
- Optionally enter today's market price to see your profit or loss.
Averaging down: use with care
Buying more after a fall lowers your average, so a smaller recovery gets you back to break even. It can work well for quality companies going through a temporary dip, and for index funds bought through a SIP. But averaging down on a business whose prospects have genuinely worsened only adds to the loss. Decide why you are buying before you look at the average.
Planning a trade? Use the brokerage calculator to see your exact costs, and the capital gains calculator to work out tax when you sell.
Frequently asked questions
How do I calculate the average price of a stock?
Multiply the quantity of each purchase by its price, add these amounts together, and divide by the total number of shares. For example, 100 shares at ₹250 and 50 shares at ₹200 cost ₹35,000 for 150 shares, an average of ₹233.33.
Does my broker show the same average price?
Usually yes for shares still held. Some brokers include charges such as brokerage and stamp duty in the average, which makes it slightly higher, and the average does not change when you sell part of a holding.
What is averaging down?
Averaging down means buying more shares after the price has fallen, which lowers your average cost. It helps only if the company is still sound; buying more of a stock that keeps falling increases your loss.
Is the average price used for capital gains tax?
Not exactly. For tax, shares are treated as sold on a first-in, first-out (FIFO) basis, so the cost and holding period come from the oldest shares you bought, not from the average price.
Sources
Last updated 19 September 2026. Results are estimates for planning only and are not investment, tax or legal advice. See our disclaimer.