Average Down Calculator

An average down calculator finds your new blended cost basis after adding to a position. Enter the shares and price of your first buy and of a second buy and the tool returns the combined share count and the weighted-average cost per share. Use it to see exactly where your break-even moves when you add to a position — and remember averaging down increases both your size and your risk.

First buy — shares First buy — price ($) Second buy — shares Second buy — price ($)

Total shares —

Average cost / share —

Runs entirely in your browser. Nothing is sent or stored.

Related metrics

R-Multiple Maximum Drawdown Expectancy

Frequently asked questions

How do you calculate average cost basis? +

Average cost = (qty1 × price1 + qty2 × price2) ÷ (qty1 + qty2) — the share-weighted average of your fills.

Is averaging down a good idea? +

It lowers your break-even but raises your position size and risk. It can work for high-conviction, well-planned entries and badly for hope-driven adds to a loser without a stop.