Analyzing Your First Rental Deal
Clear numbers beat excitement. Here’s how I look at a first rental before getting attached to the idea.
The story
I almost bought a duplex because the photos looked good and the seller said it was “cash flowing.” I ran the numbers on a napkin and convinced myself the rent would cover the mortgage. When I finally sat down with a spreadsheet, the property taxes, insurance, and vacancy ate the margin. I walked away. That experience taught me that the first analysis is less about finding a deal and more about refusing to lie to myself with incomplete numbers.
Most people start the same way. You see a listing, imagine the income, and fill in the blanks with hope. The goal of a first analysis is to replace hope with a short list of real costs and a realistic rent number. Once those are on paper, the decision becomes quieter and clearer.
Known mistakes
- Using the seller’s rent estimate without checking recent comps.
- Ignoring vacancy, repairs, and management even if you plan to self-manage.
- Forgetting property taxes and insurance when the mortgage is the only number that feels real.
- Assuming you can raise rent immediately after closing.
- Running the numbers once and never updating them after an inspection.
What I would do if I were starting over
- Write down the purchase price and realistic closing costs first.
- Look up three comparable rents in the same area and use the lowest reasonable number.
- List every recurring cost: mortgage, taxes, insurance, HOA, utilities you pay, and a monthly repair reserve.
- Add a vacancy allowance of at least one month per year until you have real history.
- Subtract all costs from rent. If the result is thin or negative, stop and move on.
- Only after the numbers work on paper, schedule an inspection and update the analysis with any new findings.
- Use the Rental Property Calculator to keep the math consistent instead of rebuilding a spreadsheet each time.
- Talk through the final numbers with someone who has no emotional stake in the property.
The first deal does not need to be perfect. It needs to survive a conservative look at income and expenses. Once you can do that calmly, the rest of the process gets easier.