One page with purchase price, closing costs, loan details, initial repairs, market rent, realistic vacancy, utilities, taxes, insurance, and a buffer is enough to start. Consistent inputs make comparisons fair, and reveal whether results reflect skill, luck, or missing assumptions.
Build a monthly cashflow timeline, sum it cumulatively, and mark the crossing where you earn back the initial outlay. Add labels for moments you can feel—first stable lease, inspection passed, refinance opportunity—so the chart becomes a story, not just arithmetic.
Comment with one project you are weighing, plus three numbers: upgrade cost, expected rent or expense change, and target payback month. We will feature instructive examples in future guides, refine the visuals together, and celebrate when your line crosses sooner than planned.