How to use this for multi-leg rolls:
• For the first roll (e.g., 135 → 100), set Original Strike and Original Premium to the call you opened on day one, and use the current BTC and new strike/premium.
• After you roll, that new call becomes your current leg.
• For any later roll (e.g., 100 → 80), treat the current call as “original”: use its strike and the premium you received for it as Original Strike and Original Premium, plus the new BTC and next strike/premium.
• If the calculator shows the New Effective Sale is lower than the original for that leg, do not roll down (you’re selling yourself out at a worse total price).
This calculator implements your one-line rule:
Only roll if (OrigPrem − BTC + NewPrem + NewStrike) ≥ (OrigPrem + OrigStrike)