Iron Butterfly Calculator

Underlying Price (current)

Short Strike (center)

Long Put Strike (lower wing)

Long Call Strike (upper wing)

Net Credit (per share)

Contracts

X-Axis Range (±% around Center Strike) Default view is ±10% around the short strike (the center). Increase to expand the view.

Results

Lower Breakeven $0.00

Upper Breakeven $0.00

Max Profit $0.00

Max Loss $0.00

Payoff Chart (Expiration)

Payoff at expiration for a standard short iron butterfly (credit). Green above $0, red below.

Iron Butterfly Options Strategy

An iron butterfly (often called an iron fly) is a defined-risk options strategy that typically collects a net credit by selling an at-the-money call and put (a short straddle) and buying protective wings (a lower-strike put and a higher-strike call). It is commonly used when you expect the underlying to stay near the center strike into expiration.

Iron Butterfly Breakevens

For a standard credit iron butterfly: Lower BE = Center Strike − Net Credit and Upper BE = Center Strike + Net Credit.

Max Profit and Max Loss

Max profit is usually the net credit received × 100 × contracts (achieved near the center strike at expiration). Max loss is limited and typically equals (wing width − net credit) × 100 × contracts.

Notes

This calculator shows expiration payoff. Real trade P&L before expiration depends on time decay, implied volatility, and bid/ask spreads. Assignment risk can exist if options are exercised early.

Iron Butterfly Calculator FAQ

Is an iron butterfly a credit or debit trade?

Most commonly it’s entered for a net credit, but it can be structured as a debit depending on strikes and pricing. This page assumes a credit iron butterfly.

What is the wing width?

Wing width is the distance from the center strike to each long strike. In a symmetric iron butterfly, both wings are the same width.

Why does the payoff look “flat” in the middle?

At expiration, maximum profit occurs when price finishes at the center strike. Inside the breakevens, payoff remains positive but slopes down toward the breakevens.