Introduction
A stock average calculator helps you find the average price you paid for a stock across multiple purchases. When you buy shares of the same stock at different prices over time, it can be hard to know your true cost per share. This tool calculates the average for you.
Enter the number of shares and the price you paid for each purchase. The calculator adds up your total investment and divides it by your total number of shares. The result is your weighted average cost per share. You can also enter the current market price to see if you have a gain or a loss on your investment.
This is useful for investors who use dollar-cost averaging, buy the dip, or simply want a clear picture of where they stand. The calculator shows a full step-by-step breakdown, a chart of how your money is spread across purchases, and an optional auto-fill feature that pulls the latest stock price by ticker symbol.
How to Use Our Stock Average Calculator
Enter your stock purchase details below to find your average cost per share, total investment, and unrealized gain or loss.
Ticker Symbol (Optional): Type a stock ticker like AAPL or TSLA and click "Auto-Fill" to pull the latest market price into a purchase row automatically.
Current Market Price (Optional): Enter the current price of the stock. This lets the calculator show your total gain or loss and percentage return.
Number of Shares: For each purchase, enter how many shares you bought. You can use whole numbers or decimals for fractional shares.
Price Per Share: For each purchase, enter the price you paid per share in dollars.
Add Purchase: Click the "Add Purchase" button to add more rows if you bought the same stock at different prices over time.
Calculate: Click the "Calculate" button to see your weighted average cost per share, total shares owned, total amount invested, and a full step-by-step breakdown of the math.
What Is a Stock Average Calculator?
A stock average calculator helps you find the average price you paid per share of a stock. When you buy the same stock more than once, you often pay a different price each time. This tool adds up all the money you spent and divides it by the total number of shares you bought. The result is your average cost per share. The math behind this is a weighted average, where each purchase is weighted by the number of shares bought.
Why Does Your Average Cost Matter?
Your average cost tells you the real price you paid for your shares. It helps you see if you are making money or losing money on your investment. If the current market price is above your average cost, you have a gain. If the current price is below your average cost, you have a loss. Knowing this number helps you make smarter choices about when to buy more shares or when to sell.
How Stock Averaging Works
Stock averaging uses a simple formula:
Average Cost Per Share = Total Amount Invested ÷ Total Shares Bought
For example, say you buy 10 shares at $50 and later buy 10 more shares at $40. You spent $500 + $400 = $900 total on 20 shares. Your average cost is $900 ÷ 20 = $45 per share.
What Is Averaging Down?
Averaging down means buying more shares of a stock after its price drops. This lowers your average cost per share. Many investors use this strategy because it means the stock does not need to rise as high for them to break even or make a profit. However, averaging down carries risk. If the stock keeps falling, you lose more money because you own more shares.
What Is Averaging Up?
Averaging up is the opposite. It means buying more shares after the price goes up. This raises your average cost, but investors do it when they believe the stock will keep growing. It is a way to add to a winning position over time.
When Should You Use This Calculator?
Use this calculator any time you buy the same stock at different prices. It works for stocks, ETFs, and other investments you purchase in multiple batches. It is especially helpful when you dollar-cost average, which means investing a fixed amount of money on a regular schedule regardless of the share price. The calculator shows your true cost basis so you can track your investment performance clearly.