How I Measure Portfolio Performance Across 12 Rental Properties

What your monthly owner statement is not telling you about your portfolio

Your property manager's owner statement tells you what happened last month. It does not tell you whether your investment is performing.

The statement shows you rent collected, expenses paid, cash in and cash out. But it cannot tell you that one of your properties is consuming 35% of its income in property taxes while another is at 20%. It cannot tell you that a turnover last spring cost you $8,000 when you add up the make-ready, the leasing fee, and the two months of lost rent. It cannot tell you that your economic rent on a $2,200 lease is actually $1,830 because your property manager needed eight weeks to get a new tenant in the door.

These are the numbers that determine whether your portfolio is building wealth or slowly eroding it. And they are not hard to calculate. You just have to know which ones matter.

I have been investing in single-family rental properties in the DFW area for 15 years and now manage a portfolio of more than ten. The difference between a portfolio that compounds and one that stalls is not just the properties you buy, though that matters a lot. It is how well they are managed after you buy them.

These are the numbers I actually track, how to calculate each one, and the cadence that makes them useful. The four metrics are inspired by the kinds of analysis that institutional investors use, but right-sized for an independent investor with 3 to 50 properties.

These four metrics are connected. A tenant turnover, for example, impacts all four at once: economic rent drops, operating costs spike, the tax ratio worsens on an empty unit, and the turnover itself carries direct costs. Understanding how they interact helps you spot problems earlier and make better decisions.

What you need before you start

Before you can calculate any of these, you need the raw inputs:

• Monthly rent rate by property (the amount on the lease)
• Monthly income collected by property (the actual cash received)
• Monthly expenses by property
• Administrative expenses: CPA, software, bank fees, etc.
• Resulting net income

If you have these, your CPA can prepare your taxes. But knowing your net income for the year is like knowing the final score without watching the game. You know the outcome, but you have no idea which plays worked and which ones hurt you so you can improve the next time.

Here are the four metrics that tell you what is actually happening inside your portfolio.

Your standard 12-month lease may be causing your vacancy problem

Speed on the make-ready is your second lever. You may want to push your carpet replacement vendor for a $200 discount, but if negotiating delays your move-in by a week, that savings gets eaten in vacancy. A week of lost rent at $1,500 per month is $375. Making fast decisions and getting ready for a move-out proactively is a key success factor in reducing vacancy.

This matters most when assessments are rising. A property with a 20% tax ratio today could drift to 28% over three years if the assessment increases and the rent does not keep pace. That is the kind of slow erosion that never shows up in any single month's statement, but it absolutely shows up in your ROI over time.

The right comparison is across your own portfolio, not against national averages. Tax rates vary so much by county and state that industry benchmarks are less useful for your specific properties. What you want to know is: which of my properties has the worst ratio, and is it getting better or worse?

Two ways to improve your tax ratio

Reset the ratio with rent increases. If you see that assessed values in an area are rising faster than your rents, you may have an opportunity for a larger rent increase, because rising values often signal rising desirability. A well-timed rent adjustment alone can reset the ratio and meaningfully improve your returns. Make sure your property manager is providing you a market comp analysis at each renewal period.

Protest your taxes every year. Property tax protesting deserves its own post, but the three main approaches are:

Unequal appraisal is where you find comparable homes that match yours according to the taxing authority's definitions of build, neighborhood, age, and condition, and demonstrate that yours has been valued unequally relative to similar properties in the area. This is the most common and often the most straightforward approach.

Condition is what you and your property manager can uniquely see about the property. Get an inspection done early each year, take photos of what needs work, and use those actual condition photos to argue the taxing authority is overvaluing your property. A rental property with deferred maintenance is not worth the same as an owner-occupied home with a new kitchen.

Income approach is when you use your actual rents to set the value, rather than the market value of a comparable home sold to a homeowner. An investor will pay less for a home than someone buying it to live in, and the amount they will pay is based on the income it generates. You can use your rents and operating costs to estimate the investment value and argue the assessed value is too high. The mechanics of this approach are well beyond this post.

If your tax ratio is above 25%, start with the rent adjustment question first. If rents are already at market, use your property inspection photos and maintenance logs to try the condition argument.

The portfolio still made money because the other eight carried the load this year. This is the value of a portfolio of rental properties: inevitably you are going to have large maintenance costs on every one of your properties, but by building up a portfolio, they usually won't all happen at once and the large expenses can be funded from the portfolio instead of your pocket.

The gap between median and average tells the story. Across my portfolio in 2025, the median monthly maintenance cost was around $1,300. The average was over $7,000, pulled up entirely by a handful of catastrophic months. That five-to-one ratio between median and average is the definition of "lumpy," and it is why looking at a single month's expenses tells you almost nothing about the operating cost profile of a property. You need the trailing 12-month view.

Not all turnovers are equal

The cause matters enormously. There are three categories, and the cost profile is dramatically different for each. The cause can give you a sense for how to improve in the future.

Voluntary vacate in good standing. The tenant bought a house, relocated for work, or simply chose not to renew. These are normal reasons to leave at the end of a lease. The property is usually in reasonable condition, the timeline is predictable, and make-ready costs tend to be modest: paint, cleaning, maybe a carpet refresh. In my portfolio, these turnovers average under $1,000 in make-ready and are re-leased within two months. These homes tend to have good performance, almost as good as a lease renewal, which is the best outcome.

Voluntary vacate driven by a fixable problem. The tenant left because maintenance was slow, the rent increase was too aggressive, or the relationship with the property manager deteriorated. These are the turnovers worth examining closely, because the cost of retention, whether that is a more responsive repair, a reasonable renewal offer, or an appliance upgrade, is almost always less than the cost of the turnover. Forgoing an additional $100 per month rent increase to retain a tenant costs $1,200 per year. Compare that to the cost of a turnover.

Assuming your monthly rent is $1,500: a new tenant lease fee to the property management company at 90% of first month's rent is $1,350. Add $1,000 to $2,000 in turnover expenses and $3,000 in vacancy expense for 2 months. Total turnover cost: $5,850. This is the value of being responsive to a good tenant who pays on time, and giving a reasonable or even modestly below market rent increase. You may feel you are spending more, but if it means you are avoiding $6,000 in turnover costs, you are way ahead.

A lease renewal fee may be $0, or costs a few hundred dollars. A full turnover costs several thousand in direct expenses plus weeks of lost rent. The math on tenant retention is not subtle.

Eviction. This is the most expensive category by a wide margin, and it is not just the make-ready costs. When a tenant stops paying and you go through the legal process, the vacancy timeline stretches from weeks to months, the property condition at handover is almost always worse, and the administrative burden multiplies. In my portfolio this year, the two eviction-driven turnovers generated 15 case files between them, involved multiple vendors, and one took over twelve months from initial notice to resolution.

Speed is the variable you can control

When I review turnover costs across my portfolio, the pattern is clear: the fast turnovers cost less, and not just because of fewer vacancy days. Speed limits the number of things that can go wrong between tenants. A unit sitting empty for a month collects problems. A pipe freezes, the lawn overgrows, a break-in attempt damages a door. Every week of vacancy is a week where costs can compound.

The operational takeaway is to make fast decisions, which requires staying on top of your email and working closely with your property manager. Get estimates lined up before the tenant moves out. Have your property manager schedule the move-out inspection the day after the vacate date, not the following week. Pre-approve standard make-ready line items so your property manager does not have to call you for approval on a $175 cleaning.

What to track at each turnover

When a turnover happens, capture these numbers before you move on:

• Total make-ready cost: every vendor invoice between tenants
• Vacancy days: from the last day of rent collected to the first day of new rent
• Lost rent: vacancy days converted to dollars at the previous lease rate
• True turnover cost: make-ready plus lost rent
• Cause: voluntary, fixable, or eviction
• Rent change: did the new lease rate go up, stay flat, or go down?

That last number is important. Most investors assume turnover at least gives them a market-rate reset. But when the market is soft you may be fortunate to get the same rent as you had before, or have to offer concessions to attract a new tenant.

Putting it together: a quarterly portfolio review

The right cadence for these metrics is quarterly, using rolling 12-month numbers.

Here is what a quarterly review looks like. Pull these four numbers for each property in your portfolio:

1. Economic rent for the trailing 12 months. Which properties had the most vacancy? Is it improving or getting worse compared to last quarter?
2. Tax ratio using the most recent annual tax bill against trailing 12-month rent. Any properties where this ratio crossed above 25%? Is it rising faster than your rent increases?
3. OpEx ratio on a rolling 12-month window. Which property is the most expensive to operate? Is the trend up or down? Is the same property showing up in the top three year after year?
4. Turnover cost for any turnovers in the past 12 months. What was the total cost per event? Were any of them preventable? What was the vacancy duration?

The value is not in any single number. It is in the outliers. When one property's OpEx ratio is double the portfolio average, that is where your attention goes. When one property's economic rent has slipped two quarters in a row, that is a conversation with your property manager. Having visibility is the key.

For the operational metrics that complement these financial numbers, like maintenance velocity, vendor cost consistency, and recurring issue patterns, see 7 Portfolio Metrics That Predict Your Rental Property ROI.