Stock average calculator: your average price, and what averaging down really does
Buy the same share three times at three prices and your broker shows one number: the average price. This stock average calculator works it out from every buy you enter, shows the running average after each purchase, your profit or loss at today’s price, and the break-even sell price once brokerage, STT, stamp duty, exchange fees, GST and the DP charge are counted.
It also answers the question people search for when a share falls: how many shares do I need to buy at the current price to bring my average down to a target? Pick a target average, an amount to invest, or a number of shares, and see the new average, the new break-even and the money involved — for Indian shares in rupees or US and other stocks in their own currency.
How to use the Stock Average Calculator
- Enter each buy — the number of shares and the price — and use Add a buy for more.
- Type today’s price in Current market price to see your profit or loss.
- Choose how to count charges: Indian delivery charges, a flat fee per order, or none.
- Under Plan your next buy, enter the new price and choose a target average, an amount or a number of shares.
- Read the new average, break-even and cost; copy the result if you want to keep it.
Stock Average Calculator features
Weighted average of any number of buys
With the average after each purchase, so you can see which buy moved it most.
Average down or up to a target
Solves for the exact number of shares — whole shares or fractional, for brokers that allow them.
Break-even after charges
STT, stamp duty, exchange and SEBI fees, GST and DP charge on Indian delivery trades, or your own flat fee.
Profit at today’s price
Unrealised profit or loss in money and percent, before and after selling charges.
Any currency
Rupees with Indian grouping, dollars, pounds, euros and more.
The stock average formula
The average buy price is a weighted average: total money spent divided by total shares, average = (q₁ × p₁ + q₂ × p₂ + …) ÷ (q₁ + q₂ + …). A plain average of the prices would be wrong whenever you bought different quantities.
To reach a target average T by buying n more shares at price X, solve (Q × A + n × X) ÷ (Q + n) = T, which gives n = Q × (A − T) ÷ (T − X), where Q is the shares you hold and A their average. The target has to lie between X and A: buying at ₹430 can pull an average of ₹478 down towards ₹430 but never below it, and the closer the target is to X, the more shares it takes.
Worked example: averaging down
You bought 100 shares at ₹520, 50 at ₹480 and 150 at ₹450: ₹1,43,500 for 300 shares, an average of ₹478.33. The share now trades at ₹430, so you are down ₹14,500 (−10.10%).
To bring the average down to ₹460 you need 300 × (478.33 − 460) ÷ (460 − 430) = 183.3 shares — 184 whole shares, costing ₹79,120, for a new average of ₹459.96 on 484 shares. Getting close to the current price takes far more money: a ₹445 target needs 667 shares (₹2,86,810). Investing a fixed ₹50,000 instead buys 116 shares and moves the average to ₹464.86.
| Target average | Shares to buy at ₹430 | Extra money |
|---|---|---|
| ₹470 | 63 | ₹27,090 |
| ₹460 | 184 | ₹79,120 |
| ₹450 | 425 | ₹1,82,750 |
| ₹445 | 667 | ₹2,86,810 |
Before you average down
- A lower average only helps if the share recovers. Ask whether you would buy it today at this price with fresh money; if not, averaging down just makes the position bigger.
- Charges raise the real break-even a little above the average price — on Indian delivery trades by about 0.2%, mostly STT on both sides.
- For tax, Indian demat shares are matched first in, first out, not at the average price. Use the stock profit calculator for the tax on a sale and the brokerage calculator for intraday or F&O charges.
- For regular fixed-amount buying rather than one-off top-ups, see the DCA calculator.
Stock Average Calculator FAQ
How do I calculate my average share price?
Add up what you paid for every buy (shares × price) and divide by the total number of shares. The stock average calculator does this and shows the average after each buy.
How many shares should I buy to average down?
n = shares held × (current average − target) ÷ (target − new price). With 300 shares at ₹478.33, buying at ₹430 to reach ₹460 takes 184 shares.
Can I average down below the current price?
No. Each new share is bought at the current price, so the average can approach that price but never reach or pass it.
Does the average price include brokerage?
Brokers usually show the average of prices only. This calculator shows both the plain average and the average including buy charges, plus the break-even after selling charges.
Is the average price used for tax in India?
No — capital gains on demat shares use first-in, first-out lots. The average is useful for tracking, not for the tax return.
Is averaging down a good strategy?
It depends on why the price fell. This page only does the arithmetic; it is not investment advice.