Understanding Cap Rate Numbers

[Rickey Miller Jr]

I'm having a bit of a difficulty understanding Cap Rate, I figured I knew my numbers on this but I can't seem to calculate the same number BP is showing on Rental Property Calculator. I've got a seller allowing me to do owner finance on a 240 month term with a 2% IR, that will balloon in five years with zero percent down. Location: Blue collar C class property. 

BP Breakdown: https://www.biggerpockets.com/...

My questions are BP is saying my Purchase Cap R is 10.87% since I'm buying it with equity built in are there two different Cap R, because i've read "Capitalization Rate = Net Operating Income / Current Market Value"? Also what specific expenses are needed to calculate regular upkeep for property? 

Scenario: 

ARV: 79,000
PP: 55,000 - 240 month term - 2% IR - 5 Year Balloon - Zero Down
Entry Fee: 1,500 (Closing cost and commision)
Principal & Interest: 278.24 
Taxes: 96.75 
Insurance: 54.58
Monthly PITI: 429.57
Current Rent: 800
Repairs: 6 %
Vacancy: 7%
Cap Ex: 6%
PM: 0%

Thank you to whom ever helps me run these numbers but I just truly am trying to get the Cap R calculation, I'm an analytical person and it's just not adding up on my end!