How to use it for earnings
Use the expiration that comes right after the earnings date. The most direct read is straddle mode: enter the stock price and the at-the-money call-plus-put price for that expiration, and the calculator returns the implied earnings move and the expected range. Alternatively, use the elevated pre-earnings implied volatility with the days remaining.
Watch the IV crush
Implied volatility runs high going into earnings and collapses immediately after — the well-known IV crush. That’s why buying options into earnings can lose even when the stock moves your way: the move has to beat the expected move and the volatility drop. The expected move is exactly the bar the stock has to clear.
TradeCaliper is a planning and education tool, not financial advice.