Stock Average Calculator
Calculate the average cost of your stock holdings across multiple purchases.
About this calculator
When you buy the same stock several times at different prices, your average cost per share is not the simple average of the prices. It is weighted by the number of shares at each price. This calculator does the weighting for you, tells you your total shares and total investment and then shows your profit or loss at any current price.
It is useful when you are averaging down after a fall or averaging up as a stock rises. Seeing the new break-even price before you buy more helps you decide if it is worth it.
How to use it
- Enter the Shares and Buy Price of your first purchase.
- Enter the second purchase in the next row. Press + Add Purchase for more.
- Press Calculate Average.
- Enter a Current Price to see your profit or loss.
Weighted average cost
Average cost = Σ (shares × price) ÷ Σ shares. Profit or loss is (Current price − Average cost) × Total shares. Brokerage and charges are not included. Add them to the cost if you want a net figure.
Worked example
100 shares at ₹500 and 50 shares at ₹400
| Total shares | 150 |
| Total cost | ₹70,000 |
| Average cost | ₹466.67 |
The simple average of 500 and 400 is 450, but you bought more at the higher price, so your true average is 466.67.
Tips and common mistakes
- Averaging down only makes sense if your belief in the company is intact. Do not add to a deteriorating business.
- Include brokerage and taxes for the true cost.
- Decide a maximum position size in advance.
- Compare the new break-even with where you think the stock can go.
- Keep a record of every buy for tax purposes.
Frequently asked questions
How do I calculate average buy price?
Multiply shares by price for each purchase, add them up and divide by the total shares.
What is averaging down?
Buying more of a stock after the price has fallen, which lowers your average cost.
Does averaging down always work?
No. If the price keeps falling you lose more. It works only if the stock recovers.
Are charges included?
No. Add brokerage and taxes to the cost yourself.
Can I add more purchases?
Yes. Use the add button.
What is break-even price?
It is the average cost. The stock must trade above it for you to be in profit.