Stock Average Calculator - Free Online Average Down & Cost Price Tool
Calculate your average buy price, total investment and break-even for any stock, ETF or crypto in seconds.
What Is a Stock Average Calculator?
A stock average calculator is a free online tool that finds the weighted average price you paid for a share when you buy the same stock more than once at different prices. Instead of working it out by hand or building an Excel sheet, you enter the quantity and price of each purchase. The calculator then returns your average cost per share, total quantity, total invested amount and break-even price in one click. It is also known as a share average calculator, stock avg calculator, average price calculator or average down calculator, and it is a simple way to understand the real numbers behind your portfolio.
Why Your Average Stock Price Matters
Your average price is your true cost basis. It decides when you reach break-even, how much profit or loss you hold, what your percentage return is and how much tax you may owe after selling. Many brokers show an average price inside their app, but a separate average stock price calculator lets you test scenarios before you place an order. You can see how buying 10, 50 or 100 more shares at a lower price changes your average, and decide whether the trade fits your plan and your risk limit.
How to Use the Stock Average Calculator
Enter the number of shares and the buy price of your first purchase.
Add a new row for every extra purchase of the same stock.
Stock Average Formula With Example
The formula uses a weighted average, because each purchase has a different quantity:
Average Price = (Q1xP1 + Q2xP2 + ... + QnxPn) / (Q1 + Q2 + ... + Qn)