How much payment can I afford?
What payment fits your real budget? Here are the parts of a payment, a worked hypothetical example, and the questions a calculator leaves out.
Your payment is four or five parts, not one
Lenders shorten it to PITI. Principal is the slice that pays down what you borrowed. Interest is the cost of borrowing, charged monthly on the remaining balance. Taxes are property taxes, estimated monthly. Insurance is your homeowners policy, also monthly. Add a fifth part when it applies: mortgage insurance, meaning PMI on a conventional loan with under 20 percent down, and a sixth for some homes: HOA dues, and in newer Sacramento-area communities, Mello-Roos assessments, which ride on the tax bill and are very easy to overlook. Early in a loan, interest is the big slice. With every payment the balance falls a little, so the interest slice shrinks and the principal slice grows. That shifting split is called amortization, and it is why extra principal early on is so powerful, and why the PMI exit dates arrive on a schedule you can predict.
Getting comfortable with the interest math
You do not need the full formula to think clearly. You need two ideas. First, monthly interest is roughly your balance times the yearly rate divided by twelve. For a hypothetical teaching example, not a quote or available rate, on a $450,000 balance at 7 percent, that is about $2,625 of interest in the first month. Second, the payment is set so that after 360 of those monthly slices, interest plus principal exactly retires the loan. Because the balance falls slowly at first, the early payments are mostly interest. That pattern is part of how a loan is repaid over time. Understanding it can make your early statements easier to follow.
Worked example (all numbers hypothetical)
Every number in this box is invented for teaching. It is not a quote, a rate offer, or a promise about any real loan.
| Home price (hypothetical) | $500,000 |
|---|---|
| Down payment, 10 percent | $50,000 |
| Loan amount | $450,000 |
| Hypothetical rate and term | 7.0 percent, 30-year fixed |
| Principal and interest | $2,994 per month |
| Property taxes, at about 1.2 percent of price per year | $500 per month |
| Homeowners insurance, at about $1,800 per year | $150 per month |
| PMI, because the down payment is under 20 percent | about $135 per month |
| Total monthly payment | $3,779 |
Notice what happened. The price was $500,000, but the honest question was never the price. It is whether $3,779 a month, plus maintenance, plus the rest of your life, fits your real budget. Change the rate by half a percent and principal and interest move by roughly $170 a month, which helps show how the rate affects the monthly amount. Remove PMI later and the payment drops by that $135 line.
Escrow: why your servicer collects taxes and insurance
The tax and insurance slices usually flow into an escrow account, a holding account your servicer manages. You pay a month's worth with each payment, the balance builds, and the servicer pays the county and your insurer when the bills land. Lenders like escrow because a tax lien would threaten their loan. It can make planning easier by spreading those bills across the year. The account is analyzed once a year. If taxes or insurance rose, your monthly escrow slice rises too, which surprises people who thought a fixed rate meant a fixed payment. The rate is fixed. The bills are not.
The lender's math versus your math
Lenders use ratio guidelines, most famously 28/36: housing costs around 28 percent of gross monthly income, all debts around 36 percent. On a hypothetical $10,000 gross monthly income, that suggests a housing payment near $2,800 and total debts near $3,600. Treat those numbers as a lender's risk tool, not as your budget. The lender does not know your childcare costs, your support of family, your savings goals, or the savings cushion that helps you feel comfortable. Your real affordability number is lower than the lender's whenever your life is more expensive than average, and the honest test is simple: could you pay this amount for twelve straight months, including a broken appliance and a normal December, without touching a credit card? If that feels tight, it may help to revisit the price range or timing before moving forward.
Run your own numbers in ten minutes
- Pick a price you have actually seen listed in your target neighborhoods, in Citrus Heights, Sacramento, Orangevale, or wherever you are looking.
- Subtract a realistic down payment. Multiply the loan amount by rough rate math, or use the worked example's ratios to estimate principal and interest.
- Add taxes at about 1.2 percent of price per year, divided by twelve, until you can get the actual parcel figures.
- Add insurance, PMI if the down payment is under 20 percent, and any HOA or Mello-Roos you find in the listing.
- Compare the total against your real monthly budget, not your gross income alone. Then add a maintenance allowance, a common planning figure is 1 percent of the price per year.
Taking a little time with the full picture can help you ask more useful questions. When you are ready to talk through the closing side of the cash, our closing costs guide covers the other half of the money.
Frequently asked questions
What is the 28/36 rule?
A long-standing lender guideline: housing costs around 28 percent of gross monthly income, all debts around 36 percent. It is a guideline lenders use, not a law and not a personal budget. Plenty of households comfortably carry more or less depending on their other costs, savings, and stability.
Why do online calculators say I can afford more?
Most ask for a price and a rate and may leave out taxes, insurance, PMI, HOA dues, and Mello-Roos assessments: a third of the real payment. Leave those out and the affordable price looks much bigger. Always compare using the full PITI total: principal, interest, taxes, and insurance.
Does a bigger down payment always win?
It lowers the loan amount, the interest paid over time, and can remove PMI, which all help. It also helps to keep savings available for moving, repairs, and everyday life. Reserves are part of affordability too.
Have a question as you read? You can call or text me at (408) 406-7900.