Chapter Eight: Exploring Housing Costs in the USA, How Much to Earn to Stay Below 30% of Income
“The rent eats first.”
Matthew Desmond
Pulitzer Prize-winning author and sociologist Matthew Desmond put the problem bluntly. Housing is usually the bill that decides whether the rest of life feels manageable or not.
A common rule of thumb says housing should stay at or below 30% of gross income. That rule is not perfect. It does not account for debt, childcare, disability, medical costs, family size, or the difference between surviving and living well. Still, it is a useful first screen. It gives us a simple way to ask whether a housing cost is probably manageable or already drifting into dangerous territory.
This chapter uses the latest official figures available on April 2, 2026, to build a worked national example. For the core numbers, it uses Freddie Mac for the 30-year mortgage rate, the U.S. Census Bureau and HUD for the median new-home sales price, and the 2024 American Community Survey for income and existing-owner and rental-cost comparisons [657,658,659].
Official Inputs for the Dated Example
As of April 2, 2026, the latest official figures available for this chapter were:
- Median new-home sales price: $400,500.00, from the U.S. Census Bureau and HUD January 2026 release [658].
- Average 30-year fixed mortgage rate: 6.38%, from Freddie Mac’s Primary Mortgage Market Survey for March 26, 2026 [657].
- Median U.S. household income: $81,604.00, from the 2024 ACS 1-year national estimates [659].
- Additional official context from the same ACS release: median gross rent was $1,487.00, median selected monthly owner costs with a mortgage were $2,035.00, median annual real-estate taxes for homes with a mortgage were $3,580.00, and the median monthly HOA or condominium fee for homes with a mortgage was $120.00 [659].
The Core Equations
Let:
- \(H\) be the home price.
- \(d\) be the down-payment rate.
- \(L\) be the loan amount.
- \(r\) be the annual mortgage rate.
- \(i\) be the monthly mortgage rate.
- \(n\) be the total number of monthly payments.
- \(M_{\text{PI}}\) be monthly principal and interest.
\[ L = H(1-d) \]
\[ i = \frac{r}{12} \]
\[ M_{\text{PI}} = L \cdot \frac{i(1+i)^n}{(1+i)^n - 1} \]
For this chapter’s dated worked example:
\[ H = \$400{,}500.00, \quad r = 6.38\%, \quad i = 0.53\%, \quad n = 360 \]
The displayed monthly rate is rounded to two decimal places. The calculations use the unrounded annual rate divided by twelve.
If you want to rerun the same mortgage math in Excel or Google Sheets, the equivalent principal-and-interest formula is =PMT(APR/12,360,-LoanAmount).
Principal-and-Interest Scenarios
The table below keeps the math honest by separating the mortgage itself from the unstable add-ons.
| Down payment | Loan amount | Monthly principal and interest | Gross annual income at 30% | Hourly wage at 2,080 hours | Multiple of the example’s median household income |
|---|---|---|---|---|---|
| 3% | $388,485.00 | $2,424.91 | $96,996.46 | $46.63 | 1.19x |
| 10% | $360,450.00 | $2,249.92 | $89,996.72 | $43.27 | 1.10x |
| 20% | $320,400.00 | $1,999.93 | $79,997.08 | $38.46 | 0.98x |
Adding Taxes, Insurance, and Association Fees
Principal and interest are only part of the story. To build a monthly housing-cost subtotal, add annual homeowners insurance \(I\), annual property tax \(T\), and monthly HOA or condominium fees \(A\):
\[ M_{\text{subtotal}} = M_{\text{PI}} + \frac{I}{12} + \frac{T}{12} + A \]
For the worked example below, the chapter uses:
\[ \begin{aligned} I &= \$4{,}200.00 \text{ per year (worked insurance estimate)} \\ T &= \$3{,}580.00 \text{ per year (official ACS median)} \\ A &= \$120.00 \text{ per month (official ACS median)} \end{aligned} \]
The insurance figure is still just a worked estimate. Insurance quotes vary too much by state, county, neighborhood, coverage level, and loss history to pretend there is one stable national number. Swap in your own quote when you rerun the math.
These subtotals exclude mortgage insurance, maintenance, utilities, and closing costs. A conventional loan with less than 20% down may require private mortgage insurance, which increases the cost of the loan [664]. The actual charge depends on the loan, lender, and borrower’s circumstances. Closing costs are upfront expenses rather than monthly charges and need a separate budget.
| Down payment | Monthly cost subtotal | Gross annual income at 30% | Hourly wage at 2,080 hours | Multiple of the example’s median household income |
|---|---|---|---|---|
| 3% | $3,193.24 | $127,729.80 | $61.41 | 1.57x |
| 10% | $3,018.25 | $120,730.05 | $58.04 | 1.48x |
| 20% | $2,768.26 | $110,730.42 | $53.24 | 1.36x |
If you want an illustrative net-income version, use an effective tax-rate assumption \(t\):
\[ Y_{\text{gross from net}} = \frac{12M_{\text{subtotal}}}{0.30(1-t)} \]
With \(t = 25.00\%\) and the 10% down monthly-subtotal example above, the required gross annual income becomes $160,973.40.
Official Rent and Existing-Owner Context
The dated example’s national median gross rent was $1,487.00 in the 2024 ACS 1-year national estimates [659]. At the same 30% rule, that points to a gross annual income of $59,480.00, or about 0.73x the example’s median household income.
The dated example’s national median selected monthly owner costs for households with a mortgage were $2,035.00 in the same ACS release [659]. At the 30% rule, that points to a gross annual income of $81,400.00, or about 1.00x the example’s median household income.
That contrast matters. Current owners often carry older loan balances and older mortgage rates. New buyers are entering a different market.
What the Numbers Are Really Saying
The first thing the math shows is that current homeowners and current buyers are not living in the same market. The 2024 ACS estimated median selected monthly owner costs of $2,035 for households with a mortgage [659]. That figure lands almost exactly on top of the 30% rule at the example’s national median household income. A new buyer financing a median-priced new home at spring 2026 rates faces a much harder picture, even before local taxes, insurance, and HOA fees are added.
The second thing the math shows is that down payment changes the picture, but it does not erase the problem. Principal and interest come down as the down payment rises. Once the example’s taxes, homeowners insurance, and association fees are included, though, the income requirement still climbs quickly. That gap in the housing stack is why people can feel misled when they only look at the mortgage calculator.
The third thing the math shows is that national rent is still lower than the new-buyer example. The 2024 ACS national median gross rent was $1,487 [659]. At the same 30% rule, that points to about $59,480 in gross annual income. The lower rent figure does not mean rent is easy. It means the median-priced new-home example is even harder.
How to Use This Chapter
Use these formulas as a measuring tool, not a prophecy. Start with the official core numbers if you want a national snapshot. Then replace the worked estimates with your own insurance quote, property-tax figure, HOA payment, mortgage-insurance cost if applicable, tax-rate assumption, and loan terms.