Enter shares and price paid for each purchase lot to calculate your average cost per share.
How to Use the Stock Average Calculator
Pick how many lots to include (2 to 5) with the buttons at the top, then enter the shares and price paid for each visible lot — total shares, total cost, and the blended average update live.
Buying the same stock at different prices over time — dollar-cost averaging, or just opportunistic buying on dips — leaves you holding one position built from several different cost bases. Averaging them down to a single number is what makes it possible to answer a simple question: am I up or down overall, and by how much?
Total Shares = Σ (shares in each lot)
Total Cost = Σ (shares × price paid, per lot)
Average Cost / Share = Total Cost ÷ Total SharesThe average isn't a simple average of the per-lot prices — it's weighted by size. Three lots at $20, $18, and $22 don't average to $20 unless every lot holds the same number of shares; a bigger lot at a lower price pulls the blended cost down further than an unweighted mean would suggest.
Hidden lot rows stay at zero and don't count toward either total, so switching from 5 lots down to 2 doesn't require clearing out the extra fields first.