A pro-forma is a hypothesis; a budget is an operating tool. This walkthrough converts your purchase analysis into a living monthly budget with checkpoints.
Start from the statement shape
Use the full line structure from our cash flow article: scheduled rent, vacancy, effective income, operating expenses by line, NOI, debt service, cash flow. The rental cash flow calculator mirrors it exactly.
Set reserves like an operator
- Maintenance reserve: a monthly line, however quiet the property looks.
- Capital reserve: a separate mental bucket for roofs, boilers and systems with known lifespans.
- Turnover reserve: a per-tenant-change cost for painting, cleaning and marketing.
Compute your break-even
Fixed annual costs divided by the contribution margin per rented month equals the occupancy you need before the property stops consuming cash. Track it quarterly with the break-even calculator.
Close the loop with actuals
Every quarter, compare actual income and expenses to the budget line by line. Update assumptions annually. The budget is a hypothesis that earns its keep by being tested.