What is a stock Average Calculator?
When you buy the same stock at different prices over time — whether averaging down after a dip or building a position gradually — your real cost basis is the quantity-weighted average of every purchase, not a simple average of the prices. Getting this number right matters for judging your actual break-even point and for capital gains reporting.
Add each buy lot's quantity and price, and optionally the current market price, to see your average cost and live profit or loss.
How the weighted average is calculated
Each lot contributes to the average in proportion to its size — a 100-share purchase moves the average far more than a 5-share one, unlike a plain average of prices.
Frequently asked questions
Does this include brokerage and other charges?
No — this calculates the average of your raw execution prices only. For an all-in cost including brokerage, STT and other charges, add them separately using the Brokerage Calculator.
Should I include sold lots?
No — only include lots you currently hold. If you’ve partially sold a position, most brokers reduce your holding on a FIFO basis, which changes the average of what remains.
Is averaging down always a good idea?
Not necessarily — it lowers your break-even price but also increases your exposure to a stock that’s already fallen. It’s worth being deliberate about why you’re adding, not just mechanical about the maths.