butterfly spread breakeven prices

of the 2 breakeven prices for the butterfly spread, i cant figure out the 2nd… 2(mid-call) - Xlow-call - premiums, for the life of me. in my mind i feel like cheap call should appreciate until the price of the middle calls, before it gets called away.

The high breakeven is just the high strike minus the cost of the butterfly.

High Strike - (high call price + low call price - 2*mid call price)

They way I remember it:

BE1 + X(L) + C(L) - 2C(MID) + C(H)

Go other direction and flip signs

BE2 = X(H) - C(L) + 2C(MDI) - C(H)

This assumes H/L calls are even distance from MID.

wow, so basically low strike + premiums and high strike - premiums. u could have saved me 2 hours of my life

pretty evident if you look at the diagram too.

it is a 45 degree line from the strike to the 0 profit line one backward from Hi Strike and one forward from the Low Strike.