Stock Average Calculator
Enter the quantity and price of each purchase to find your average buy price, total shares and invested amount — and add a current price to see your profit or loss.
Average price = total amount invested ÷ total shares. This is your cost basis before brokerage, STT and other charges, which slightly raise your effective buy price.
What is stock averaging?
When you buy the same stock at different prices, your average buy price (or cost basis) is the single price that represents your whole position. It is simply the total money you invested divided by the total number of shares — and it's the number you compare against the current price to know whether you're in profit or loss.
The formula
Average price = Total amount invested ÷ Total shares bought
That distinction is the difference between a weighted average and a plain one. The simple mean of ₹100 and ₹80 is ₹90, but weighting each price by the number of shares bought at it gives ₹86.67 — the figure that actually reflects your money. To take a weighted average of any set of numbers, or a plain mean, median and mode of a list, use the average calculator.
Averaging down — and its risk
Buying more of a stock as its price falls ("averaging down") lowers your average cost, so the price needs to recover less for you to break even. It's a common strategy, but it only works if the company is fundamentally sound — averaging down on a permanently declining business just increases your loss. Never average down purely because a price is lower; do it only when your original thesis still holds.
| Purchase | Shares | Price | Amount |
|---|---|---|---|
| Buy 1 | 10 | ₹100 | ₹1,000 |
| Buy 2 | 20 | ₹80 | ₹1,600 |
| Buy 3 | 30 | ₹60 | ₹1,800 |
| Total | 60 | ₹73.33 avg | ₹4,400 |
Share average calculator, stock average calculator — the same tool
These terms are used interchangeably in Indian markets, and this calculator serves all of them. Whether you call it a share average calculator, a stock average price calculator, an average share price calculator or a cost-basis calculator, the arithmetic is identical: total money invested divided by total units held. Brokers and financial media in India tend to say "share", while international and app interfaces tend to say "stock" — there is no difference in the calculation.
You may also see the result labelled differently depending on where you look. Your broker's holdings screen might call it average price, avg. cost, average cost, average trading price or buy average; a tax statement will usually call it cost of acquisition or cost basis. All describe the same blended figure this page computes.
How many shares to average down to a target price?
This is the question most people actually have when a holding is underwater: not "what is my average?" but "what would it take to get my average down to ₹X?" You can work it out directly. If you hold Q shares at an average of A, and the price is now P, the number of extra shares N needed to reach a target average T is:
N = Q × (A − T) ÷ (T − P)
Take a holding of 100 shares bought at an average of ₹100, now trading at ₹70 — a 30% paper loss needing a +42.9% recovery just to break even. Here is what each target average would cost:
| Target average | Shares to buy at ₹70 | Extra capital | Multiple of original ₹10,000 | Break-even move then needed |
|---|---|---|---|---|
| ₹95 | 20 | ₹1,400 | 0.14× | +35.7% |
| ₹90 | 50 | ₹3,500 | 0.35× | +28.6% |
| ₹85 | 100 | ₹7,000 | 0.70× | +21.4% |
| ₹80 | 200 | ₹14,000 | 1.40× | +14.3% |
| ₹75 | 500 | ₹35,000 | 3.50× | +7.1% |
| ₹72 | 1,400 | ₹98,000 | 9.80× | +2.9% |
The cost does not rise steadily — it accelerates sharply. Halving your paper loss from ₹100 to ₹85 costs ₹7,000, about 70% of your original stake. Pushing on to ₹75 costs ₹35,000, three and a half times the original. Getting to ₹72 costs nearly ten times it. Each further rupee of improvement buys less than the last.
Read the last column before deciding. Averaging from ₹100 to ₹85 cuts the recovery you need from +42.9% to +21.4% for 0.7× your original stake — often a reasonable trade if your view on the company still holds. Chasing ₹72 to shave the requirement to +2.9% means committing ten times your original position to a stock that has already fallen 30%. That is no longer averaging down; it is concentrating risk. Size the addition against your whole portfolio, not against the loss you are trying to erase.
Don't forget charges
On Indian exchanges (NSE and BSE), your true cost basis is slightly higher than the simple average because of brokerage, STT (Securities Transaction Tax), exchange fees and GST on those charges. For long-term investors these are small, but for frequent traders they add up. The average here is your pre-charge cost — useful for tracking a position, though your break-even price is a little above it.
Averaging vs systematic investing
Deliberately buying a fixed rupee amount at regular intervals — rather than reacting to price drops — is the disciplined cousin of averaging, and for mutual funds it's exactly what a SIP does. To judge how a position has actually performed over time, use the CAGR calculator; for a one-time investment's growth, the lumpsum calculator helps.
Frequently Asked Questions
How many shares should I buy to average down to a target price?
Can I average down below the current market price?
Does averaging down reduce how much the price must recover?
How do I calculate the average price of a stock?
What does averaging down mean?
Is a lower average price always better?
Does this calculator include brokerage and taxes?
How do I find my profit or loss?
Can I average more than three purchases?
What is cost basis?
Method
This calculator uses standard mathematics, not a statutory rate, so there is nothing here that can go out of date. The formula it applies is:
Weighted average price = total amount invested ÷ total shares held = Σ(quantity × price) ÷ Σ(quantity).
To reach a target average T from a holding of Q shares at average A, buying at price P, the shares needed are N = Q(A − T) ÷ (T − P). Because a weighted average always lies between the old average and the new purchase price, no finite N reaches a target at or below P.