I’m Mike Fisher with MF CashFlow Property Management, part of M Property Group LLC, a Licensed Illinois Real Estate Broker. Every week I’m talking to an owner who bought a property on cap rate and can’t figure out why the cash isn’t there at the end of the month. Cap rate vs cash flow for Chicago suburbs rental property is one of the most misunderstood topics in this business, and after 35 years investing in real estate, I’ve seen that confusion cost good people real money. Here’s how an operator actually looks at it.
Cap Rate Is a Comparison Tool, Not a Business Plan
Cap rate is net operating income divided by purchase price. That’s it. And here’s what a lot of people miss: there’s no mortgage in that formula. Cap rate assumes you paid all cash for the property. It’s useful for comparing deals across submarkets. A 7-cap in Matteson versus a 5.5-cap in Oak Lawn gives you a starting point for a real conversation about risk and return. But it doesn’t tell you how much money hits your account after the loan payment clears.
People see a solid cap rate, feel good about a deal, put a mortgage on it, and then wonder where the profit went. That’s the trap.
Cash Flow Is What You Actually Run On
Cash flow is what’s left after everything’s paid. Mortgage. Property taxes. Insurance. Management fees. Maintenance reserves. Vacancy allowance. All of it. That number, whatever it is, is your operational reality. It’s what deposits into your account and funds your next deal, or it doesn’t.
I’ve seen properties with a strong cap rate go cash flow negative the minute financing hits them. I’ve also seen properties with a modest cap rate cash flow well because the owner locked in great terms at the right time. The cap rate didn’t change. The real-world outcome did. Run the actual numbers in our ROI calculator before you make any moves on a deal.
Property Taxes in the Chicago Suburbs Can Blow Up a Cap Rate
Property taxes in the south and west suburbs are significant, and Cook County reassesses on a triennial cycle, meaning your tax bill can shift meaningfully every three years. When a seller shows you a cap rate, they’re baking their current tax bill into the NOI. If a reassessment just happened, or one’s coming soon, that number may already be wrong.
I’ve seen buyers get sold on a cap rate built on last year’s taxes, then take a 20-25% hit at reassessment. The NOI drops, the effective cap rate is worse than advertised, and the cash flow they underwrote doesn’t exist. Before you trust any seller’s proforma, check the Cook County Assessor’s Office for the current assessed value and where that property sits in the reassessment cycle. That context belongs in your underwriting, not your regrets.
How I Actually Judge a Rental Deal
Here’s my sequence. What can this property actually rent for in today’s market? Not the owner’s number, not a rough guess, but what comparable units are leasing for right now. If you don’t know, start with a free rental analysis before you touch anything else in the math.
Then I build the full expense stack: taxes, insurance, management, maintenance reserve (I run 8-10% of gross rents), vacancy reserve (5-8% depending on submarket), and any capital expense I can see coming in the next few years. That’s true NOI. Then debt service goes on last. What’s left is real cash flow. If that number works, I use cap rate to benchmark where the deal sits relative to the market. Cash flow first. Cap rate as context. And don’t forget depreciation: the IRS lets you write off residential rental property over 27.5 years per IRS Publication 527, which is a real tax benefit even in a positive cash flow year and belongs in your total return picture.
Management Costs Belong in Every Proforma
Whether you’re self-managing or paying someone, management is a real cost. Your time has a value, and if you’re paying too much, or not getting what you’re paying for, it hits your returns directly. Know what management should actually cost in this market before you finalize any numbers. I’ve seen too many owners underestimate this line item and then wonder why actual cash flow doesn’t match what they projected going in.
FAQ: Cap Rate vs Cash Flow, Chicago Suburbs Rental Property
What’s a good cap rate for rental properties in the Chicago south and west suburbs? Most submarkets I work in run somewhere between 6% and 9%, depending on location, condition, and property type. But a cap rate that doesn’t cash flow after financing isn’t actually a good deal. Context matters more than the number itself.
Can a rental property have a high cap rate but still have negative cash flow? Yes, and it happens more than people expect. High cap rates often signal higher risk, rougher submarkets, or deferred maintenance. If your financing costs eat the spread, you’re cash flow negative regardless of what the headline number says. Always run the debt service before you decide anything.
Should I use cap rate or cash flow when deciding whether to sell a rental property? Cash flow. If a property is producing consistent income with solid tenants in place, I’d think hard before selling. Cap rate matters more when you’re benchmarking what you’re buying next, especially in a 1031 exchange where you need to compare your replacement options.
If you’ve got a rental and you’re not sure the numbers are actually working for you, or you’re sizing up a deal and want a second set of eyes on it, let’s talk. Book a call with me and we’ll go through your specific situation.
