Expected move & breakeven calculator
Enter the stock price, implied volatility and days to expiry. The calculator shows the one standard deviation range the market prices in. Add a call or put with strike and premium to see its breakeven and how it compares with that range.
Model estimate based on implied volatility (lognormal, no interest or dividends). Real moves can be larger, especially around earnings.
How the expected move is calculated
Expected move ≈ stock price × IV × √(trading days ÷ 252)
Calendar days are converted to trading days with 252 ÷ 365. A $200 stock with IV of 30 % and 25 trading days has an expected move of about $18.90, a range of roughly $181 to $219. Under the model, the stock ends inside the 1σ range in about two of three cases and inside the 2σ range in about 95 %. More on the expected move and implied volatility.
How to use the breakeven check
A long call breaks even at strike plus premium, a long put at strike minus premium. If the move needed to reach breakeven is larger than the expected move, the option is expensive for the idea: the stock has to beat what the market already prices in. That is the trap behind cheap far out-of-the-money options, see delta.
Frequently asked questions
What is the expected move of a stock?
The range the options market prices in for a period, based on implied volatility. It is a one standard deviation range, not a price target, and says nothing about direction.
Why use trading days and 252?
Implied volatility is quoted per year of about 252 trading days. The square root of days ÷ 252 scales it down to your period.
Does the calculator account for earnings?
Only through the IV you enter. Before earnings IV is usually higher, which widens the expected move; after the report it often drops sharply.
Is the probability a forecast?
No. It is a model estimate from implied volatility under simplifying assumptions. Real price moves are often larger than the model suggests.