Math check help needed, please! CoC calculations all off...

[Andrew Marino]

Hey everybody--first time here, first time posting! I'm running Cash-on-Cash calculations on a property i'm interested in. They all look good and correct, except for my worst-case scenario, when I assume all my units are empty. I have an asking price of $139,000 with a 30% down payment (32,700), closing costs at 2% (2180), rehab budget of $5000, monthly expenses of $681 (or $8,172 annually). When I divide my total investment by my total expenses to get my CoC, I'm left with -20.49%. OK, fine. To mitigate that, let's reduce the down payment to 25% (or $27,250). Now my negative CoC INCREASES to -23.74%. Why is my loss increasing percentage-wise when I'm lower my down payment? Shouldn't I have a smaller loss? I can't figure this out. What am I doing wrong...?