Know the number
before you fall in love.
Everyone starts with Zillow. Wrong order. The budget comes first, the house comes second. Not because it's more fun. Because it's the only order that ends with you keeping the house. Here's the real lesson on what your budget is actually telling you.
What a budget
actually does.
The lender's number isn't your number.
A lender will approve you for the maximum payment that keeps your DTI under 43%. Your life will approve you for the payment that still leaves room for groceries, a car breaking, and a kid growing out of shoes every 90 days. Those are two different numbers. You want the second one.
The 28/36 rule is a starting line. Not a finish.
Traditional advice: housing payment under 28% of gross income, total debts under 36%. It's a reasonable floor. But it doesn't know your commute, your insulin co-pay, or that you're trying to save for a kid's college. Use the rule as a starting point, then stress-test against your actual life.
Budget the all-in payment. PITI + everything else.
PITI = Principal, Interest, Taxes, Insurance. Plus HOA if you have one. Plus mortgage insurance if you're under 20% down. Plus utilities, which scale with square footage. Plus maintenance (budget 1% of home value per year — that's a real number). If the all-in payment is $400/mo higher than rent, that's what you're comparing.
Down payment isn't the only cash at closing.
Closing costs run 2–5% of purchase price. Earnest money is 1–3% (refundable but held). Moving costs, immediate repairs, a new appliance because the old one is 22 years old. Plan on total cash-to-close being down payment + 4% — minimum. DPA programs absorb a lot of this. Many buyers don't know that.
An emergency fund is the mortgage you don't default on.
Homeowners who enter ownership with less than 3 months of expenses saved default at 4x the rate of those who enter with 6+ months. It's not what anyone wants to hear. It is, to date, the single strongest predictor of whether a first-time buyer keeps the house. Budget the fund. Close with it intact.
Five steps.
One honest number.
- 01
Open your bank statements from the last 90 days.
Not your budget app's guess. Actual outflows. Print or export. You'll find $200–$400/mo you didn't know existed.
- 02
Categorize into Fixed / Flexible / Flagged.
Fixed = rent, insurance, student loans. Flexible = groceries, gas, utilities. Flagged = delivery, subscriptions, takeout. The third column is where the budget lives.
- 03
Subtract the totals from net take-home.
What's left is your realistic housing-payment capacity — NOT the number the pre-approval generator spit out. If the two disagree, trust yours.
- 04
Run the Budget Builder with YOUR numbers.
The Budget Builder will tell you what price range that realistic payment supports. It's usually 10–25% less than the lender's max. That's by design.
- 05
Save the output. Label it 'Step 01 — my budget.'
You'll reference this every time a Zillow search tempts you into a higher tier. Keep the file. Print it. It's a tool against emotion, not a one-time exercise.
Run the Budget Builder.
Plug in your real numbers. Get a honest housing-payment ceiling and the price range it supports.
Open Budget Builder →Four ways
this step gets faked.
Using gross income instead of net.
Lenders underwrite on gross. You live on net. If your take-home is 72% of gross after taxes + retirement, plan on that.
Forgetting property taxes double the payment in some counties.
A $300K house in a 2.5% county is $625/mo in taxes alone. Same house in a 0.9% county is $225. Check the county rate before falling in love with a zip.
Assuming rent = mortgage.
Rent is total cost. Mortgage is PI only. You'll add taxes, insurance, PMI, maintenance, and utilities yourself. The true cost ratio is usually 1.3–1.6x the PI number.
Maxing out the approval.
If your pre-approval says $350K, aim at $280–300K. The $50K of headroom is what protects you the month a transmission dies or the HVAC gives up.
Step 01: complete.
On to Credit.
Budget told you what you can afford. Credit decides what the market will charge you. Step 02 is the other side of the same math — and the one most people are leaving money on the table in.