Butterfly Calculator
A long call butterfly buys the K1/K3 wings and sells 2× the K2 call (K1<K2<K3, evenly spaced). Enter strikes and premiums to estimate PnL.
Results
Fill in the inputs and click Calculate.
- Expiry PnL
- –
- Max Loss
- –
- Max Profit
- –
- Lower Break-Even
- –
- Upper Break-Even
- –
Risk disclaimer
This calculator shows theoretical single-settlement PnL (USDT/contract) with symmetric-wing limit estimates; fees excluded.
What is a butterfly for?
A low-cost, low-risk short-volatility structure: if expiry lands near the middle strike K2 you approach the max profit.
Upside and downside are both capped and the loss is limited to the net debit.
How to use
- Enter the three strikes (K1<K2<K3).
- Enter the premiums paid on K1/K3 and received per K2 short.
- Enter your expected expiry price and click Calculate for PnL and break-evens.
Formula
- Net Debit = K1 + K3 Premium − 2×K2 Premium
- At K2 the payoff ≈ (K2−K1); Max Profit ≈ (K2−K1) − Net Debit
- Max Loss = Net Debit; BE ≈ K1 + Debit / K3 − Debit
Example
K1=95 @5, K2=100 short 2 legs @2 each, K3=105 @1 → debit 2. Expiry 100 → PnL = 5−2 = 3.
Max loss 2; break-evens ≈ 97 / 103.
FAQ
How wide is the profit zone?
Between the two break-evens, peaking at K2; width depends on the debit.
Even spacing?
Classic butterflies assume equal spacing; the limit formulas rely on it.