Newbie needing assistance with number crunching

[Jay Gill]

As the subject implies I am just at the learning stage when it comes to commercial real estate investing.  I am just running a few hypothetical numbers based on hypothetical down payment. I am just analyzing the results and assessing how realistic they are.

Assuming I have a 500k down payment.

A)Cash on Cash return( desired is 10%) = cashflow / Down payment(500K)

Cash flow = 50K

B)Then determine desired Net operating income, assuming 30 amortization and 35% down at 4.5% interest rate

NOI = Cash flow + Debt

NOI = (50K) + (928,571 @ 4.5%, 30 amortization)

NOI = (50K) = (4,705 mthly *12months)

NOI = 106,460

C)Desired cap rate,

Purchase Price / NOI = Cap Rate

1,428, 571 / 106,460 =  13.4% 

Assuming I didn't mess up my math.  Is a 13.4% cap rate realistic?  Also any other suggestions in terms how I could improve my analysis based on numbers. As an aside I know there many other factors when analyzing a deal, but at this point I want to get a feel for the numbers.