Rental numbers for ZIP 78663 (Round Mountain, TX)
Negative cash flow at any interest rate with 25% down: the rent does not cover operating costs and principal.
- Gross yield
- 2.5%
- rent x 12 / price
- Est. cap rate
- -0.3%
- NOI / price
- Cash flow
- -$4,822/mo
- at 7.78%, 25% down
- Typical price
- $852,000
- Zillow ZHVI, Aug 2026
- HUD Fair Market Rent
- $1,760/mo
- HUD Fair Market Rent, 2 bedroom, FY2026
The pro forma
Typical home, default assumptions
| Operator | Line | Amount | Source |
|---|---|---|---|
| Gross rent | $21,120 | ||
| Vacancy | $1,056 | ||
| Management | $1,605 | ||
| Property tax | $9,285 | ||
| Insurance | $3,437 | ||
| Maintenance | $8,518 | ||
| Net operating income | -$2,781 | ||
| Loan payments | $55,083 | ||
| Cash flow | -$57,864 |
| Operator | Line | Amount | Source |
|---|---|---|---|
| Typical price | $851,832 | ||
| Down payment (25%) | $212,958 | ||
| Loan | $638,874 | ||
| Rate | 7.78% | ||
| Monthly payment | $4,590 | ||
| Cash in | $238,513 | ||
| Cash-on-cash return | -24.3% | ||
| DSCR | -0.05 | ||
| Break-even rate | none |
Assumptions
Change them in the calculator- Down payment25%
- A common minimum for investment-property and DSCR loans.
- Interest rate7.78%
- Freddie Mac 30-year 7.03% (week of 2026-09-24) + 0.75 point investor premium.
- Loan term30 years
- Fixed, fully amortising.
- Closing costs3% of price
- Added to cash invested.
- Insurance$3,437 a year
- NAIC 2023 average homeowners (HO-3) premium for Texas, $2,864, x 1.2 for a landlord policy.
- Maintenance1% of price a year
- The 1% rule of thumb; older homes run higher.
- Vacancy5% of rent
- About 18 days empty a year.
- Management8% of collected rent
- A typical full-service fee; zero if you self-manage.
Trends
Five years to August 2026
- Price, 12 months
- -1.9%
- Rent, 12 months
- n/a
- no Zillow rent series here
- Rent minus price growth
- n/a
- positive means yields are improving
Show the numbers
| Month | Typical value |
|---|---|
| Aug 2021 | $740,872 |
| Aug 2022 | $911,546 |
| Aug 2023 | $918,097 |
| Aug 2024 | $898,344 |
| Aug 2025 | $868,333 |
| Aug 2026 | $851,832 |
Rent references
Two sources, never blended
| Source | Studio | 1 bed | 2 bed | 3 bed | 4 bed |
|---|---|---|---|---|---|
| HUD Small Area FMR, FY2026 | $1,400 | $1,490 | $1,760 | $2,240 | $2,600 |
| Zillow observed rent, Aug 2026 | not published for this ZIP | ||||
HUD's Fair Market Rent is the 40th percentile gross rent (rent plus utilities) for a standard unit, and it is what Section 8 vouchers pay against. Zillow's index tracks asking rents on listed homes. The two measure different things, so they are shown side by side and never averaged. HUD area: Austin-Round Rock-San Marcos, TX MSA.
Property tax
- Effective rate
- 1.09%
- ZIP area, ACS
- At the typical price
- $9,285/yr
Median real estate taxes paid divided by median home value, Census ACS 2020 to 2024. Blanco County: 0.93%. Actual bills depend on the assessment, exemptions and any non-homestead rate.
Supply
- Permits per 1,000 households
- 1.6
- Blanco County, last 12 months
- National percentile
- 21th
- among US counties
8 new housing units permitted in 2025-09 to 2026-08, Census Building Permits Survey. A high figure means more new supply competing for tenants.
Nearby ZIP codes
| ZIP | Distance | Typical price | Rent | Gross yield | Cash flow /mo |
|---|---|---|---|---|---|
| 78657Horseshoe Bay | 8.5 mi | $635,000 | $1,410 | 2.7% | -$3,512 |
| 78636Johnson City | 9.6 mi | $602,000 | $1,760* | 3.5% | -$2,916 |
| 78669Spicewood | 11.4 mi | $701,000 | $3,383 | 5.8% | -$2,335 |
| 78654Marble Falls | 12.4 mi | $398,000 | $1,582 | 4.8% | -$1,773 |
| 78620Dripping Springs | 16.8 mi | $678,000 | $2,323 | 4.1% | -$3,200 |
| 78639Kingsland | 18.7 mi | $433,000 | $1,040* | 2.9% | -$2,331 |
| 78645Lago Vista | 20.4 mi | $416,000 | $2,085 | 6.0% | -$1,561 |
| 78738Austin | 20.7 mi | $841,000 | $2,177 | 3.1% | -$4,384 |
* HUD Fair Market Rent, 2 bedroom (no Zillow rent index for that ZIP).
Run the numbers on a real listing
The calculator opens with this ZIP's figures. Swap in a listing's price and rent, your rate and your costs.
Open the calculator for 78663Questions
- Is 78663 good for rental property?
- On the typical home here, priced at $852,000 and renting for $1,760 a month (HUD Fair Market Rent, 2 bedroom, FY2026), the gross yield is 2.5% and the estimated cap rate is -0.3%. At a 7.78% investor rate with 25% down, estimated cash flow is -$4,822 a month. The median gross yield across the 8,418 ZIP codes with full Zillow data is 5.6%. These are figures for a typical property, not a judgement on any particular one.
- What is the typical rent in 78663?
- Zillow does not publish a rent index for 78663. HUD's FY2026 Small Area Fair Market Rent for a 2-bedroom here is $1,760, the 40th percentile of gross rents and the basis for Section 8 payment standards.
- What is the property tax rate in 78663?
- The effective property tax rate is about 1.09% of value (median taxes paid divided by median home value, Census ACS 2020 to 2024). On the typical $852,000 home that is about $9,285 a year. Your bill depends on the assessment and local exemptions.
- What interest rate makes a rental in 78663 break even?
- With the default assumptions, no interest rate brings cash flow to zero: rent does not cover operating costs plus principal on a 30-year loan with 25% down.
- How fast are prices and rents changing in 78663?
- Over the 12 months to August 2026, the typical home value changed -1.9%.
Sources and method
- Zillow Home Value Index (ZHVI), mid tier, smoothed and seasonally adjusted
Zillow Research. Read: 2026-08.
Typical home value by ZIP, county, metro and state, and the price trend.
- HUD Small Area Fair Market Rents, FY2026
US Department of Housing and Urban Development. Read: FY2026.
Rent by bedroom count for every ZIP. The rent used on tier B pages, and a reference on all pages. It is the 40th percentile gross rent, so it runs below market.
- American Community Survey 5-year estimates, 2020 to 2024 (B25103 median real estate taxes paid, B25077 median home value, B11001 households)
US Census Bureau. Read: 2020 to 2024.
Effective property tax rate (median taxes paid divided by median value) by ZIP code tabulation area, county and state; households for the permits ratio.
- Freddie Mac Primary Mortgage Market Survey, 30-year fixed (FRED series MORTGAGE30US)
Freddie Mac via the Federal Reserve Bank of St. Louis. Read: 2026-09-24.
The weekly 30-year rate. The site adds a disclosed investor premium to it for the loan payment.
- Building Permits Survey, county monthly files
US Census Bureau. Read: 2025-09 to 2026-08.
New housing units permitted in the last 12 months per 1,000 households, a supply-pressure signal.
- NAIC Homeowners Insurance Report, data for 2023
National Association of Insurance Commissioners. Read: 2023.
Average HO-3 homeowners premium by state, multiplied by 1.2 as a landlord-policy assumption.
Data: Zillow Research (ZHVI, ZORI), HUD, US Census Bureau, Freddie Mac. Every formula is on the methodology page.
Estimates from public data for a typical property. Not investment, tax or legal advice. Your property, financing and costs will differ.