Calculating your average price per share is straightforward once you know the Stock Average formula and what each input means. This guide explains the method in plain language, walks through a manual calculation, and gives worked examples you can follow — then you can do it instantly with the Stock Average Calculator.
What is Stock Average?
The Stock Average calculation tells you your average price per share from a few simple inputs. The figure you are solving for here is the average price per share, expressed in INR.
The Stock Average formula
The core formula is:
Average price per share = (First purchase quantity × First purchase price + Second purchase quantity × Second purchase price) ÷ (First purchase quantity + Second purchase quantity)Here is what each input means:
- First purchase quantity — a number. Example: 100.
- First purchase price — a money amount. Example: ₹50.
- Second purchase quantity — a number. Example: 100.
- Second purchase price — a money amount. Example: ₹40.
How to calculate it step by step
- Write down the first purchase quantity (for example, 100).
- Write down the first purchase price (for example, ₹50).
- Write down the second purchase quantity (for example, 100).
- Write down the second purchase price (for example, ₹40).
- Apply the formula above to get your average price per share.
- Double-check the result with the Stock Average Calculator.
Worked examples
Example 1
| Input / Output | Value |
|---|---|
| First purchase quantity | 100 |
| First purchase price | ₹50 |
| Second purchase quantity | 100 |
| Second purchase price | ₹40 |
| Average price per share | ₹45.00 |
| Total shares | 200 |
| Total invested | ₹9,000 |
With first purchase quantity of 100, first purchase price of ₹50, second purchase quantity of 100 and second purchase price of ₹40, the average price per share works out to ₹45.00.
Example 2
With first purchase quantity of 200, first purchase price of ₹50, second purchase quantity of 100 and second purchase price of ₹40, the average price per share works out to ₹46.67.
| Result | Value |
|---|---|
| Average price per share | ₹46.67 |
| Total shares | 300 |
| Total invested | ₹14,000 |
Example 3
With first purchase quantity of 50, first purchase price of ₹50, second purchase quantity of 100 and second purchase price of ₹40, the average price per share works out to ₹43.33.
| Result | Value |
|---|---|
| Average price per share | ₹43.33 |
| Total shares | 150 |
| Total invested | ₹6,500 |
Tips for an accurate result
- Keep your units consistent — mixing, say, months with years or grams with kilograms is the most common source of error.
- Round only at the very end. Rounding inputs early can shift the final answer noticeably.
- Re-run the numbers whenever an input changes, rather than estimating from an old result.
- Annual rates must be converted to the period you are calculating for (for example, divide an annual rate by 12 for a monthly figure).
Prefer not to do the maths by hand? — the Stock Average Calculator does it instantly, for free, with the formula and a worked example built in.
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