If you can read a bank statement, you can learn to underwrite a rental property. The math isn't complicated — what trips up most first-time landlords isn't the formulas, it's knowing which inputs to use and where to find them. Here is a 7-step framework built specifically for Texas rental properties, with DFW-specific benchmarks where they matter most.
Step 1 — Estimate Gross Rent Realistically
Your gross rent estimate is the foundation of everything that follows. If it's wrong, every calculation downstream is wrong. Use Zillow Rent Zestimate, Rentometer, or better — contact a local property manager who can pull actual comparable active listings and recent lease data from NTREIS MLS.
DFW rents vary sharply by submarket. A 3-bedroom, 2-bath home in Mesquite rents differently than the same spec in Frisco. Even within a single city, rents can vary significantly block by block based on school district, proximity to employment, and condition. Use the conservative end of the range — if comparable rents span $1,600–$1,850, model $1,650.
Annual Gross Rent = Monthly Rent × 12
Step 2 — Build In Vacancy
No property is rented 12 months out of 12 every year. Tenants move, leases turn, and there are always gaps between move-out and the next tenant's move-in. DFW historically runs 5–8% vacancy on stabilized single-family rentals, but for new acquisitions where you have no leasing history yet, use 8–10% in your model.
Effective Gross Income (EGI) = Annual Gross Rent × (1 − Vacancy Rate)
At $1,700/month with 8% vacancy: EGI = ($1,700 × 12) × 0.92 = $18,768/year.
Step 3 — Account for Every Expense
This is where most underwriting errors happen. Landlords commonly model only the expenses they can see — mortgage and taxes — and miss several others that are just as real. Here's the full list:
| Expense | DFW Benchmark | Notes |
|---|---|---|
| Property Taxes | 1.8%–2.5% of assessed value | Pull actual tax certificate; add MUD/PID overlays |
| Insurance | $1,200–$2,000/yr | Get an actual landlord policy quote before closing |
| HOA Dues | Verify with HOA | Request resale certificate under TX PC §207 |
| Maintenance Reserve | 10%–15% of gross annual rent | Older properties budget higher; new construction 7%–10% |
| Property Management | $99/mo flat (ManageWithEXL) or 8–10% of collected rent elsewhere | Flat fee saves more as rent increases |
| Leasing / Vacancy Cost | Already modeled in Step 2 | ManageWithEXL charges $0 vacancy fee |
Step 4 — Calculate NOI
Net Operating Income is what the property earns before you factor in debt. It's the fundamental measure of a rental property's performance as a standalone asset.
NOI = Effective Gross Income − Total Annual Operating Expenses
Operating expenses include everything in the table above — taxes, insurance, HOA, maintenance, and management. They do not include mortgage principal or interest, which are financing costs, not operating costs.
Step 5 — Calculate Cap Rate
Capitalization rate measures the annual return the property generates relative to its purchase price, as if you bought it with all cash. It's the cleanest apples-to-apples comparison across properties because it removes the effect of financing.
Cap Rate = NOI ÷ Purchase Price
DFW stabilized single-family rentals in established submarkets generally trade at 4%–6% cap rates. A 5% cap rate on a $300,000 purchase means the property generates $15,000 NOI per year before debt service. Cap rates above 6%–7% in DFW often signal elevated risk — higher maintenance burden, challenging tenant pool, or soft rental demand — rather than simply a better deal.
Step 6 — Calculate Cash-on-Cash Return
Cash-on-cash return measures the actual cash return on the real dollars you put into the deal — down payment, closing costs, and any upfront repairs. It's the metric most relevant to leveraged buyers because it captures the effect of your mortgage.
Annual Cash Flow = NOI − Annual Debt Service
Cash-on-Cash Return = Annual Cash Flow ÷ Total Cash Invested
A 6%–8% cash-on-cash return on a DFW rental in the current rate environment is generally considered solid. Sub-4% CoC in a high-interest-rate environment means the property is working hard to break even on annual cash flow — acceptable if you're counting on appreciation, but know what you're signing up for.
Step 7 — Know Your Break-Even Rent
Break-even rent tells you the minimum monthly rent you need to cover all operating costs and debt service. It defines your margin of safety. The wider the gap between break-even rent and actual market rent, the more buffer you have against vacancy, rent softening, or unexpected expenses.
Break-Even Rent = (Total Annual Operating Expenses + Annual Debt Service) ÷ 12
If market rent is $1,700 and your break-even is $1,550, you have a $150/month buffer. If market rent softens 10% and drops to $1,530, you're in negative cash flow territory. Knowing your break-even before you buy tells you exactly how much risk the deal carries.
The 50% Rule of Thumb
A widely used quick filter: operating expenses (excluding debt service) on a typical rental property tend to run approximately 50% of gross rent over time. This rule exists because landlords consistently underestimate the cumulative cost of taxes, insurance, maintenance, vacancy, and management when they model on a best-case basis.
The 50% rule is not a substitute for running the actual numbers on a specific property. In Texas, where property taxes are disproportionately high, expense ratios on many DFW rentals run 45%–55% of gross rent depending on submarket and property age. Use it as a quick sanity check — if your model shows 30% expenses, something is missing from your analysis.
How Property Management Fees Affect the Math
Management fees seem like a small line item until you run them across a portfolio over multiple years. With a percentage-based property manager charging 8–10% of collected rent, a $1,700/month property costs $136–$170/month in management fees — $1,632–$2,040/year. As rent grows, so does that cost.
With ManageWithEXL's $99/month flat fee on the Essential plan, that same $1,700/month property saves $37–$71/month in management cost — $444–$852/year. Across a five-property portfolio held for five years, the difference between a percentage-based fee and a flat fee can exceed $20,000 in retained cash flow. That's not a rounding error — it compounds meaningfully.
Own a DFW rental?
ManageWithEXL handles the full management stack — $0 vacancy fee, $0 maintenance markup, flat monthly fee from $99. Let's run the actual numbers on your property and show you exactly what your NOI and cash-on-cash return look like with flat-fee management.