Cap Rates Explained for Seattle Rentals (With Honest Math)
What a cap rate is, how to calculate NOI, and why the number looks low on Seattle rentals — a plain-English guide with fully illustrative examples.
A capitalization rate (cap rate) is a property’s annual net operating income divided by its price. If a property nets $24,000 a year and costs $600,000, its cap rate is 4% ($24,000 ÷ $600,000). It answers one question: ignoring financing, what does this property earn as a percentage of what it costs?
That’s the whole formula. The skill is in computing the top number honestly — and in understanding why the result tends to look unimpressive in the Seattle metro.
NOI: where every cap rate lives or dies
Net operating income (NOI) is gross rent minus operating expenses, before any mortgage payment. Two people can quote wildly different cap rates on the same property simply by being more or less honest about expenses. A defensible NOI subtracts:
- Vacancy and credit loss — no unit is occupied 100% of the time, and not every tenant pays every month.
- Property taxes — in King County these are substantial and reassessed regularly (here’s how King County property taxes work).
- Insurance — landlord policies cost more than homeowner policies.
- Maintenance and repairs — ongoing, not just emergencies.
- Capital reserves — roofs, water heaters, and furnaces die on schedules that don’t care about your spreadsheet.
- Management — even if you self-manage, your time has a market price; an honest underwrite includes it.
- Utilities, landscaping, and any HOA dues the owner pays.
What NOI does not subtract: the mortgage. That’s deliberate — the cap rate measures the property, not your financing. It’s what makes cap rates comparable across buyers who put different amounts down.
A fully worked (and fully made-up) example
These numbers are illustrative only — invented to show the method, not to describe any real market or property.
| Line item | Annual amount |
|---|---|
| Gross scheduled rent ($2,800/mo) | $33,600 |
| Vacancy allowance (5%) | −$1,680 |
| Property taxes | −$6,000 |
| Insurance | −$1,800 |
| Maintenance + reserves | −$3,400 |
| Management allowance | −$2,700 |
| Net operating income | $18,020 |
On a $650,000 purchase, that’s $18,020 ÷ $650,000 = a 2.8% cap rate. Notice what happened: gross rent looked like 5.2% of the price, but honest expenses cut the real yield nearly in half. That gap — between the seller’s breezy pro forma and your skeptical rebuild — is where bad purchases happen.
Why Seattle cap rates look “low” — and what that actually means
In expensive coastal metros, cap rates on ordinary residential rentals tend to sit low, because purchase prices are high relative to rents. That’s not a bug in your math; it’s the market telling you something: buyers here have historically been paid in appreciation, not yield. A low cap rate is the price of owning in a supply-constrained, high-wage region that investors expect to grow.
Three practical consequences:
- Compare cap rates to your alternatives. If a property’s honest cap rate is below what you could earn in a risk-free account, the purchase only makes sense if you believe in rent growth, appreciation, tax benefits, or some combination — and you should be able to say which.
- Compare cap rates across similar properties, not across asset classes. A small Tacoma fourplex and a Capitol Hill condo aren’t priced off the same expectations, and their cap rates encode different risk and growth assumptions.
- Don’t chase the highest number blindly. A high cap rate usually signals higher perceived risk — tougher tenancy profiles, deferred maintenance, weaker growth prospects — not free money.
Cap rate vs. cash-on-cash: don’t mix them up
The cap rate ignores your loan. Cash-on-cash return doesn’t — it’s your annual pre-tax cash flow after the mortgage, divided by the actual cash you invested. With today’s investor financing, it’s entirely possible for a property to have a positive cap rate and negative cash-on-cash return — meaning you feed it every month. If you’re financing the purchase (most first-timers are — see DSCR and investor loans in Washington), you need both numbers, and our mortgage calculator can rough out the debt-service side.
How sellers and agents bend the number
Watch for these in any listing pro forma:
- “Market rent” instead of actual rent — the cap rate of a hypothetical tenant.
- Missing vacancy and reserves — the two lines optimists always delete.
- Last year’s tax bill — your assessment will reflect your purchase price eventually.
- “Pro forma cap rate” labeled in fine print — a projection dressed as a fact.
Rebuild every NOI yourself from rent rolls and real bills. If the seller won’t provide them, that’s your answer.
Where this fits in your decision
The cap rate is a sorting tool, not a verdict. It tells you which properties deserve a deeper look and makes the Seattle-metro yield-vs-appreciation trade-off visible in one number. It doesn’t capture financing, taxes (talk to a CPA about depreciation and your bracket — it changes real returns meaningfully), or the operational realities covered in Before You Become a Landlord in Washington.
And when a purchase does pencil, remember that transaction costs are part of the denominator. Agent fees vary more than most investors assume — Manaky Homes lets you compare what Greater Seattle agents actually charge, side by side and free. Get on the waitlist and make the fee a number you chose, not one you inherited.
