By Ramesh Sharma Calculating the average share price is one of the most important skills for stock market investors. Whether you invest in stocks regularly through SIPs or buy shares at different prices over time, knowing your average purchase price helps you understand your actual investment cost and determine your profit or loss.
In this article, we’ll explain how to calculate the average share price, the formula used, practical examples, and why it matters for investors.
What Is the Average Share Price?
The average share price is the weighted average cost of all the shares you have purchased in a particular company. It represents the average amount you have paid per share after making multiple purchases at different prices.
For example, if you buy shares of the same company several times over months or years, your average share price combines all those purchases into one cost per share.
This average helps investors make informed decisions about buying, holding, or selling their investments.
Average Share Price Formula
The formula for calculating the average share price is:
Average Share Price = Total Investment Amount ÷ Total Number of Shares Purchased
Where:
- Total Investment Amount = Sum of money spent on all share purchases
- Total Number of Shares = Total shares purchased across all transactions
This method is also called the weighted average cost method because it considers both the purchase price and the number of shares bought.
Example 1: Simple Average Share Price Calculation
Suppose you purchase shares in three transactions.
| Purchase | Shares Bought | Price Per Share | Total Investment |
| First Purchase | 20 | ₹100 | ₹2,000 |
| Second Purchase | 30 | ₹120 | ₹3,600 |
| Third Purchase | 50 | ₹90 | ₹4,500 |
Now calculate:
Total Shares = 20 + 30 + 50 = 100 shares
Total Investment = ₹2,000 + ₹3,600 + ₹4,500 = ₹10,100
Average Share Price:
₹10,100 ÷ 100 = ₹101 per share
Therefore, your average share price is ₹101.
Example 2: Averaging Down
Many investors buy additional shares when prices fall to reduce their average purchase cost.
Suppose:
- First purchase: 100 shares at ₹200
- Second purchase: 100 shares at ₹150
Total investment:
₹20,000 + ₹15,000 = ₹35,000
Total shares:
100 + 100 = 200
Average share price:
₹35,000 ÷ 200 = ₹175 per share
Although your first purchase was at ₹200, buying additional shares at a lower price reduced your average cost to ₹175.
This strategy is commonly known as averaging down.
Example 3: Averaging Up
Sometimes investors continue purchasing shares even after prices rise because they expect further growth.
Suppose:
- Buy 50 shares at ₹300
- Buy another 50 shares at ₹400
Total investment:
₹15,000 + ₹20,000 = ₹35,000
Total shares:
100
Average share price:
₹35,000 ÷ 100 = ₹350 per share
In this case, the average purchase price increases because additional shares were purchased at a higher price.
Why Is Average Share Price Important?
Knowing your average share price offers several benefits.
1. Calculates Actual Profit or Loss
Your profit depends on the difference between the current market price and your average purchase price.
For example:
- Average share price = ₹250
- Current market price = ₹300
Profit per share:
₹300 − ₹250 = ₹50
Without knowing your average cost, you cannot accurately calculate your investment returns.
2. Helps Make Better Selling Decisions
Investors often use the average purchase price as a benchmark before deciding whether to sell or continue holding a stock.
If the market price is significantly above the average cost, investors may choose to book profits.
3. Supports Long-Term Investing
Long-term investors frequently buy shares at different prices over several years.
Calculating the average share price provides a clearer picture of the overall investment rather than focusing on individual purchases.
4. Reduces Emotional Investing
Instead of worrying about every market fluctuation, investors can focus on whether the current market price is above or below their average purchase price.
This encourages more disciplined investment decisions.
Does Brokerage Affect the Average Share Price?
Yes.
For more accurate calculations, investors should include:
- Brokerage charges
- Securities Transaction Tax (STT)
- Exchange transaction charges
- GST
- Stamp duty
- SEBI charges
The adjusted formula becomes:
Average Share Price = Total Cost of Shares (Including Charges) ÷ Total Shares Purchased
Most brokerage platforms automatically calculate this figure in your trading account.
Average Share Price vs Current Market Price
Many beginners confuse these two terms.
| Average Share Price | Current Market Price |
| Cost at which you purchased shares | Price at which the stock is currently trading |
| Remains unchanged unless you buy more shares | Changes continuously during market hours |
| Used to calculate profit or loss | Used for buying and selling shares |
Understanding the difference helps investors accurately assess their portfolio performance.
Common Mistakes While Calculating Average Share Price
Investors should avoid these common errors:
- Ignoring brokerage and transaction charges.
- Using a simple average instead of a weighted average.
- Forgetting to include all purchase transactions.
- Mixing shares bought from different accounts without proper records.
- Assuming the current market price is the same as the average purchase price.
Maintaining accurate records of every transaction ensures correct calculations.
Conclusion
The average share price is the weighted average cost of all the shares you have purchased in a company. It is calculated by dividing the total investment amount by the total number of shares purchased. This simple calculation helps investors measure their actual investment cost, determine profits or losses, and make better buying and selling decisions.
Whether you are a beginner or an experienced investor, regularly tracking your average share price can improve your investment strategy and provide a clearer understanding of your portfolio’s performance over the long term.