How to Analyze a Rental Property in 10 Minutes (With a Free Calculator)

Good deals don't wait for slow underwriting. When a listing hits your inbox in the morning, the investors who move first aren't guessing — they're running a disciplined 10-minute screen that kills bad deals fast and flags the ones worth a full underwrite.

Here's that screen, step by step. And if you'd rather not build the spreadsheet, our free rental calculator runs this exact sequence — plug in six numbers, get the verdict.

Minute 0–2: Pin Down Real Income

Start with the listing's rent number, then make it honest.

Scheduled rent is the fantasy number: $2,100/month × 12 = $25,200/year. Effective income is what you actually underwrite: subtract vacancy and collection loss. Use 5–8% for single-family rentals in most markets — never 0%. At 7%, your $25,200 becomes $23,436 of effective income.

Add other income if it exists: pet rent, parking, laundry, storage. Small on SFR, but $50/month in pet rent is $600 a year most beginners leave on the table.

Rule: every expense percentage from here on is calculated against effective income, not gross rent. That one discipline fixes half of all amateur analyses.

Minute 2–6: Build Expenses Line by Line

This is where deals die, and where most 10-minute screens cheat. Don't use a flat percentage. Budget each line: property taxes (pull the actual bill from the county assessor — taxes re-price at your purchase price, not the seller's decade-old basis), insurance (get a real quote), maintenance (5–8% of effective income), CapEx reserves (5–8% — a $9,000 roof with 15 years left is $50/month), property management (8–10%, even if you'll self-manage), HOA, utilities you carry, lawn/pest as applicable.

If your total operating expenses land under 35% of gross rent on a single-family rental, you're probably missing something. Go back and find it.

Minute 6–8: NOI, Cap Rate, Cash-on-Cash

Net Operating Income (NOI) = effective income − operating expenses. This is the property's true operating profit before financing — the single most important number in the analysis.

Cap rate = NOI ÷ purchase price. A $13,900 NOI on a $285,000 price is a 4.9% cap. Compare it to what's actually trading in that market, not a national average.

Cash-on-cash return = annual cash flow after mortgage payments ÷ your total cash invested. This is your return — the number that tells you whether the deal beats your alternatives.

Minute 8–10: The DSCR Gate and the Verdict

DSCR (Debt Service Coverage Ratio) = NOI ÷ annual mortgage payments. Most residential investment lenders want 1.20–1.25x. If your deal needs a DSCR under 1.0 to work, it doesn't work — it's losing money every month.

Then the verdict, and be honest about it: GO (clears your thresholds with realistic inputs), REVIEW (close, but only works if one assumption holds — flag which one), or KILL (fails the math — archive it and move on).

The Stress Test (Bonus 2 Minutes)

Before you call it a GO, break it: +1% interest rate, −5% rent, 10% vacancy. If the deal only survives the base case, it's not a deal — it's a forecast wearing a costume.

Skip the Spreadsheet

This whole workflow — income, line-by-line expenses, NOI, cap rate, cash-on-cash, DSCR, and a GO/REVIEW/KILL verdict — is exactly what our free rental calculator does. Six inputs, the full math, no signup.

Try the free rental calculator → https://www.mydealready.ai/free-rental-calculator

And when a deal survives the 10-minute screen and deserves the full treatment — 5-year projections, scenario modeling, refinance analysis — the SFR Investment Proforma runs the complete underwrite in about 20 minutes. https://dealready.gumroad.com/l/ublvr

Educational content, not financial advice. Verify rents, taxes, insurance, and expenses against your local market before making investment decisions.