How the math works
Long Call: Breakeven = Strike + Premium. Max loss = Premium paid (limited). Max gain is theoretically unlimited.
Long Put: Breakeven = Strike − Premium. Max loss = Premium paid. Max gain = Strike − Premium (occurs if stock goes to zero).
Bull Call Spread: Buy lower-strike call, sell higher-strike call. Net debit = long premium − short premium. Max gain = (Strike Spread − Net Debit) × 100. Max loss = Net Debit × 100.
Bear Put Spread: Buy higher-strike put, sell lower-strike put. Net debit = long premium − short premium. Max gain = (Strike Spread − Net Debit) × 100. Max loss = Net Debit × 100.
Things this calculator does not model
- Time decay (theta) before expiration
- Implied volatility changes (vega)
- Early assignment risk on American options
- Commission and fees
For at-expiration P/L only. For mid-trade Greeks and IV modeling, use a dedicated options analytics platform.