Cost Per Share Calculator
Ahmed mamadouh
Cost Per Share Calculator
Use this calculator to determine the average cost you paid for each share of a stock or investment. This is a fundamental metric for understanding your investment performance and calculating profits or losses.
Enter the total amount you paid for your shares (including commissions, if applicable) and the total number of shares you acquired.
Enter Investment Details
Calculation Result
Understanding Cost Per Share
What is Cost Per Share?
Cost Per Share (or Cost Basis Per Share) represents the average price paid for each share of a security, including any commissions or fees associated with the purchase. It's crucial for calculating capital gains or losses when you sell shares.
Formula
The formula is straightforward:
Cost Per Share = Total Amount Paid / Total Number of Shares
For example, if you paid $1050 total for 10 shares, your cost per share is $1050 / 10 = $105 per share.
Why is it Important?
Knowing your cost per share helps you:
- Determine profitability: If the current market price is higher than your cost per share, you have a potential gain. If it's lower, you have a potential loss.
- Calculate taxes: Capital gains or losses are calculated based on the difference between the selling price and the cost basis (which is related to cost per share).
- Compare investments: You can compare your average purchase price to current prices to evaluate different positions in your portfolio.
Cost Per Share Examples
Click on an example to see the details:
Example 1: Simple Purchase
Scenario: You buy 50 shares of a stock for a total cost of $2,500.
Input: Total Amount Paid = $2500, Total Number of Shares = 50
Calculation: Cost Per Share = $2500 / 50
Result: Cost Per Share = $50.00
Conclusion: Your average cost for each share is $50.00.
Example 2: Purchase with Commission
Scenario: You buy 10 shares at $98 per share, and pay a $7 commission.
Input: Total Amount Paid = (10 * $98) + $7 = $980 + $7 = $987, Total Number of Shares = 10
Calculation: Cost Per Share = $987 / 10
Result: Cost Per Share = $98.70
Conclusion: Including the commission, your cost per share is $98.70.
Example 3: Multiple Purchases (Average Cost Basis)
Scenario: You first buy 100 shares for $1000 total. Later, you buy another 50 shares for $600 total.
Input: Total Amount Paid = $1000 + $600 = $1600, Total Number of Shares = 100 + 50 = 150
Calculation: Cost Per Share = $1600 / 150
Result: Cost Per Share = $10.67 (approximately)
Conclusion: Your average cost basis across both purchases is about $10.67 per share.
Example 4: Small Purchase
Scenario: You buy 5 shares for a total of $35.
Input: Total Amount Paid = $35, Total Number of Shares = 5
Calculation: Cost Per Share = $35 / 5
Result: Cost Per Share = $7.00
Conclusion: Each share cost you $7.00 on average.
Example 5: Large Number of Shares
Scenario: You acquire 1000 shares for a total cost of $15,000.
Input: Total Amount Paid = $15000, Total Number of Shares = 1000
Calculation: Cost Per Share = $15000 / 1000
Result: Cost Per Share = $15.00
Conclusion: Your average cost per share is $15.00.
Example 6: Fractional Shares
Scenario: You invest $50 into a stock whose current price is $100 per share. You receive 0.5 fractional shares.
Input: Total Amount Paid = $50, Total Number of Shares = 0.5
Calculation: Cost Per Share = $50 / 0.5
Result: Cost Per Share = $100.00
Conclusion: Your cost per share for this fractional purchase is $100.00.
Example 7: High Stock Price
Scenario: You buy 2 shares of a high-priced stock for a total cost of $3,500.
Input: Total Amount Paid = $3500, Total Number of Shares = 2
Calculation: Cost Per Share = $3500 / 2
Result: Cost Per Share = $1750.00
Conclusion: The average cost for each of these shares is $1750.00.
Example 8: Low Stock Price
Scenario: You buy 500 shares of a penny stock for a total cost of $150.
Input: Total Amount Paid = $150, Total Number of Shares = 500
Calculation: Cost Per Share = $150 / 500
Result: Cost Per Share = $0.30
Conclusion: Your average cost per share is $0.30.
Example 9: Round Numbers
Scenario: You spend exactly $1000 to buy shares at $20 each.
Input: Total Amount Paid = $1000, Total Number of Shares = 50 (since $1000 / $20 = 50)
Calculation: Cost Per Share = $1000 / 50
Result: Cost Per Share = $20.00
Conclusion: Your cost per share matches the price because there were no extra fees in this simple example.
Example 10: Zero Shares (Invalid Input)
Scenario: You accidentally enter 0 for the number of shares.
Input: Total Amount Paid = $500, Total Number of Shares = 0
Calculation: Division by zero
Result: Error
Conclusion: The calculator will return an error because you cannot divide by zero. The number of shares must be greater than 0 to calculate a cost per share.
Frequently Asked Questions
1. What does Cost Per Share mean?
It's the average price you paid for each share of a stock, including any associated transaction costs.
2. How is the "Total Amount Paid" calculated?
It's the total money spent to acquire the shares. This typically includes the price of the shares themselves plus any brokerage commissions or fees charged for the transaction.
3. Should I include commissions in the "Total Amount Paid"?
Yes, including commissions gives you your accurate cost basis, which is important for calculating capital gains/losses for tax purposes.
4. What if I bought the same stock multiple times at different prices?
You should add up the total amount paid for ALL purchases and the total number of shares from ALL purchases. The calculator will then give you the *average* cost per share across all those transactions.
5. Can I calculate cost per share for fractional shares?
Yes, absolutely. Enter the exact total amount paid for the fractional shares and the exact total number of fractional shares acquired (e.g., 0.75 shares).
6. Why would I get an error if I enter 0 for the number of shares?
You cannot divide by zero. If you acquired 0 shares, you don't have any shares to calculate a cost per share for. The number of shares must be a positive value.
7. Does this calculator work for different currencies?
Yes, it works for any currency. Just ensure that "Total Amount Paid" is in the same currency you are dealing with. The "Cost Per Share" result will be in that same currency.
8. Is Cost Per Share the same as the current market price?
No. Cost per share is what *you paid* on average. The current market price is what the stock is trading for *right now*. The difference is your potential profit or loss.
9. How is Cost Basis related to Cost Per Share?
Cost Basis is usually the total amount paid for a position (shares * price + fees). Cost Per Share is simply the Cost Basis divided by the number of shares, giving you the average cost *per share*.
10. What are the typical fees included in "Total Amount Paid"?
Common fees include brokerage commissions (per trade or per share), SEC fees, and FINRA fees. The calculator assumes you include all such costs in the "Total Amount Paid" figure.
