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.
Worked example: what averaging down actually does to your breakeven
Buy 100 shares at ₹500, and your average (and breakeven) price is simply ₹500. If the price falls and you buy another 100 shares at ₹400, your position becomes 200 shares at a ₹90,000 total cost — a new average of ₹450. The stock now only needs to recover to ₹450, not back to your original ₹500, for the combined position to break even.
That’s the mechanical benefit of averaging down. It doesn’t change whether the stock was a good buy in the first place — it only lowers the bar for the position as a whole to turn positive, while also doubling your rupee exposure to a stock that has already fallen once.
Average price vs. cost basis for tax purposes
The weighted average this calculator produces is useful for judging your break-even point, but it isn’t automatically how the tax department treats a partial sale. Under Indian tax rules, share sales are typically matched on a FIFO (first-in, first-out) basis — the earliest lot you bought is treated as the first lot you sell, each retaining its own purchase price and holding period for capital-gains calculation, rather than everything blending into one average cost. Your shares themselves are held electronically through a depository — NSDL or CDSL, depending on which your broker uses — and it’s your broker’s or depository’s transaction statement, not this calculator, that holds the authoritative lot-by-lot record for tax filing. Keep that record, not just the blended average, for accurate tax filing.
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.
What’s the difference between averaging down and rupee-cost averaging in a SIP?
They sound similar but differ in intent: a SIP invests a fixed amount on a fixed schedule regardless of price, automatically buying more units when prices are low. Averaging down a stock is a discretionary, one-off decision to add more at a lower price — it isn’t on autopilot, and requires actively deciding the stock is still worth owning more of.
Does this work for mutual fund units too?
The same weighted-average maths applies to any asset bought in multiple lots at different prices, including mutual fund units — though for a fund bought via SIP, the Mutual Fund Calculator or XIRR Calculator will usually be more directly useful.
How many buy lots can I add?
As many as you need — use "+ Add buy lot" for each separate purchase at a different price.
What does the unrealised P&L figure assume?
It multiplies your total quantity by the current market price you enter and compares that to your total invested cost — it’s a paper gain or loss on your full holding, before any brokerage or taxes that would apply if you actually sold.