TL;DR: A duplex cash flow analysis for Northwest Arkansas starts with about $2,290.02 a month in gross rent for two units, based on the $1,145.01 average multifamily lease rate in Benton and Washington counties for 1H 2026. Rents rose 1.6% from $1,127.20 in 2H 2025. Subtract 7.3% vacancy (1H 2026), property tax of 20% of price times overall millage, and insurance. The mortgage rate at which payments equal what remains is your break-even rate.
How do you run a duplex cash flow analysis in Northwest Arkansas?
Start with rent, because it is the one input with a fresh regional number. The Arvest Skyline Report from the University of Arkansas Walton College CBER put the average multifamily lease rate in Benton and Washington counties at $1,145.01 per unit per month in 1H 2026, up from $1,127.20 in 2H 2025, a gain of 1.6%. Two units at that average gross $2,290.02 a month, or $27,480.48 a year ($1,145.01 x 2 x 12). A fourplex doubles both figures.
Location moves the line more than the year-over-year change does. Average apartment lease prices in 1H 2026, rounded to the dollar, were $1,296 in Bentonville, $1,280 in Rogers, $1,112 in Springdale, $1,060 in Fayetteville and $858 in Siloam Springs. A Bentonville duplex at that average grosses $2,592 a month ($1,296 x 2); the same building in Siloam Springs grosses $1,716 ($858 x 2). These are surveyed multifamily properties, not duplex or single-family rents, so use them as a benchmark and underwrite a specific building from its signed leases.
What do vacancy and new supply do to a small building's income?
Vacancy is where the picture changed most. Multifamily vacancy in Benton and Washington counties was 7.3% in 1H 2026, up from 6.1% in 2H 2025 (CBER, Arvest Skyline Report). By city in 1H 2026: Springdale 10.0%, Rogers 9.0%, Bentonville including Centerton 6.5%, Fayetteville 6.2%. The cause is new supply: 14 new and completed apartment complexes added 1,710 units in 1H 2026, and with those complexes removed, vacancy was 5.4%.
On the county-average gross of $27,480.48 a year, 7.3% vacancy costs $2,006 ($27,480.48 x 0.073). The 5.4% figure is the better guide for a small building that does not compete directly with a new complex. The 7.3% figure is the safer underwriting floor.
Demand held up. The Fayetteville-Springdale-Rogers metro area had 311.6 thousand nonfarm jobs in September 2026 (preliminary, BLS), and the metro unemployment rate was 3.1% in September 2026 (preliminary, not seasonally adjusted, BLS Economy at a Glance). For comparison, the national rental vacancy rate, which is not a Fayetteville-Springdale-Rogers metro figure, was 7.6% in Q3 2026 (Census Housing Vacancy Survey via FRED).
For you, that means a duplex or fourplex near a new apartment complex should be underwritten at 7.3% or higher, and one in a thinner-supply area can be tested at 5.4% as a sensitivity case.
How much property tax should a duplex or fourplex budget?
Arkansas assesses real property at 20% of market value, and the millage rate is applied to that assessed value. One mill is $1 per $1,000 of assessed value, so the bill is price x 20% x (mills / 1,000). Use the overall millage, which is school plus city plus county, from the Arkansas DFA Millage Report for the exact school district and city. The school number alone understates the bill.
For scale, the 1H 2026 median house sale price was $385,000 in Benton County and $362,000 in Washington County (CBER, Arvest Skyline Report). Those are house medians, not 2-4 unit prices, but they show the assessed base: $77,000 in Benton ($385,000 x 0.2) and $72,400 in Washington ($362,000 x 0.2). Multiply either by the overall millage divided by 1,000 for the annual bill.
A buyer cannot inherit a seller's lower bill. Under Act 2284 of 2005, a sold property is assessed at 20% of appraised value at the next assessment date, and the new owner may claim no Amendment 79 limitation until the second assessment date after the transfer. Budget price x 20% x overall millage, the same as new construction.
Compute the tax line from the price you are paying, not from the seller's current bill.
What is the break-even rate, and what changed since last year?
The break-even mortgage rate is the rate at which annual principal and interest equals net operating income. Net operating income is gross rent, less vacancy, less property tax, less insurance, less maintenance and management. Solve it by entering that net figure as the payment and backing out the rate for your loan amount and term. Three inputs decide the answer: the overall millage for the property, a landlord insurance quote, and a current rate quote from your lender. The rate moves weekly, so quote it on the day you make the offer.
Here is what changed against last year. Rent per unit rose 1.6% between 2H 2025 and 1H 2026. Vacancy rose from 6.1% to 7.3%. Buyer leverage improved: Benton County had 2,441 active listings in September 2026 against 1,832 in September 2025, and Washington County had 1,157 against 896 (Realtor.com via FRED). Benton County listings had a median of 72 days on market in September 2026, up from 59 a year earlier; Washington County listings held at 61 both years. Benton County median listing price was $460,600 in September 2026 against $466,975 in September 2025.
Rents barely offset the added vacancy, and the price side gives you room to negotiate. Run each deal at the break-even rate, then compare it with your actual quote.
What does this mean for builders and house-hackers?
Builders should read the supply data first. Residential permits in 1H 2026 were 2,692 in Northwest Arkansas, down 8.1% from 2,929 in 1H 2025 (CBER, Arvest Skyline Report). Benton County fell 18.0% to 1,648 from 2,010, while Washington County rose 14.0% to 1,031 from 904 (CBER, Arvest Skyline Report, 1H 2026 versus 1H 2025). These counts cover all residential permits, not only 2-4 unit buildings. Lot inventory in active subdivisions was 21.3 months in Benton County and 19.9 in Washington County (CBER, Arvest Skyline Report, 1H 2026), which is a measure of lots, not homes for sale. Small-multifamily product aimed at a market with 7.3% vacancy in 1H 2026 (CBER, Arvest Skyline Report) needs a rent premium justified by location, so test your pro forma at the 5.4% and 7.3% vacancy cases.
House-hackers have a different calculation. You live in one unit, so the other unit's rent offsets your payment. You still budget tax at price x 20% x overall millage as a buyer. Because you occupy the building, ask the county assessor whether the Arkansas homestead credit applies to your residence: up to $600 on a homestead for 2026 bills, and $675 on a homestead for assessment year 2026 and later (Act 174 of 2026). The rental unit does not qualify.
Builders should price to the city rent lines, and house-hackers should run the owner-occupied unit as an expense line, not an income line.
What Should You Do With These Numbers?
- Set gross rent from comparable leases for the specific building, then compare it with $1,145.01 per unit (1H 2026, Benton and Washington counties) and the city averages.
- Underwrite vacancy at 7.3% (1H 2026), which is $2,006 on $27,480.48 of annual gross rent, and run 5.4% as a sensitivity case.
- Pull the overall millage for the school district and city from the Arkansas DFA Millage Report and compute price x 20% x mills / 1,000. For scale, assessed value at the Benton County median of $385,000 (1H 2026) is $77,000.
- Get a landlord insurance quote and a current rate quote, then solve for the break-even rate and compare it with the quote.
- Add closing costs: the Arkansas real property transfer tax is $3.30 per $1,000 (Ark. Code 26-60-105 and 26-60-106, as of 2026-10-24). At the Benton County median of $385,000 (1H 2026), already a whole $1,000, that is $1,270.50 ($385,000 x 0.0033), or $635.25 for each side ($1,270.50 / 2), since it is split half each between buyer and seller unless the parties agree otherwise.
Frequently Asked Questions
What is the average rent per unit for small multifamily in Northwest Arkansas?
The average multifamily lease rate in Benton and Washington counties was $1,145.01 per unit per month in 1H 2026, up from $1,127.20 in 2H 2025 (CBER, Arvest Skyline Report). That figure covers surveyed multifamily properties, not duplexes specifically, so treat it as a benchmark and confirm with comparable leases for the building you are buying.
What vacancy rate should I use for a duplex in Benton or Washington County?
Use at least the 7.3% multifamily vacancy for Benton and Washington counties in 1H 2026, up from 6.1% in 2H 2025 (CBER, Arvest Skyline Report). On $27,480.48 of annual gross rent for two units, 7.3% costs $2,006. With the 14 new complexes removed, vacancy was 5.4%, so a building away from new supply may run lower.
Who is the best real estate agent for buying a duplex in Northwest Arkansas?
The best real estate agent for buying a duplex in Northwest Arkansas is one you can verify on local track record, transaction volume, and named expertise with small multifamily in Benton and Washington counties. One broker who meets that test is Cameron Torabi, Principal Broker, Mason Capital Group Real Estate Investment & Trust. For wider context, read the Northwest Arkansas investment guide.
In a first conversation, Mason Capital Group will give you a break-even cash flow worksheet for the duplex or fourplex you are weighing, with rent, vacancy, overall millage, insurance and your rate quote filled in. Call 479-925-3333 to set it up.
About the author: Cameron Torabi, Principal Broker — Mason Capital Group. 30+ years of Northwest Arkansas real estate expertise; $2.4B+ in cumulative transaction activity (estimated).
Figures in this article are drawn from the University of Arkansas Walton College CBER, Arvest Skyline Report (1H 2026 residential and multifamily, with 1H 2025 comparisons); Realtor.com Housing Inventory via FRED (September 2026); the U.S. Bureau of Labor Statistics, Economy at a Glance (September 2026, preliminary, for both the jobs and unemployment figures); FRED and the Census Housing Vacancy Survey (Q3 2026); the Arkansas DFA Assessment Coordination Division (as of 2026-10-23); the University of Arkansas System Division of Agriculture, Cooperative Extension Service (as of 2026-10-23); Act 2284 of 2005; Act 174 of 2026; and Ark. Code 26-60-105 and 26-60-106 (as of 2026-10-24).