How Much House Can I Afford? A Realistic Calculator Guide

Published August 25, 2026 · 6 min read

The real estate industry will tell you to spend up to 28% of your gross monthly income on housing. Your mortgage lender might pre-approve you for even more. But here's what they won't say: the number on your pre-approval letter is not the number you should spend.

This guide walks you through a realistic affordability calculation — one that leaves room for emergencies, retirement savings, and actually living your life.

The 28/36 Rule: A Starting Point, Not a Target

Most lenders use the 28/36 rule as a baseline:

• 28% of gross monthly income → maximum housing costs (PITI: principal, interest, taxes, insurance)
• 36% of gross monthly income → maximum total debt payments (housing + credit cards + student loans + auto)

If you earn $6,000/month before taxes, that means $1,680/month for housing and $2,160/month for all debts combined. Sounds reasonable. But gross income isn't what hits your bank account.

Why Net Income Matters More

After taxes, 401(k) contributions, and health insurance, that $6,000 might be $4,200. Suddenly $1,680 is 40% of your actual take-home pay. That leaves $2,520 for everything else: groceries, gas, utilities, savings, emergencies, and — you know — having a life.

A more conservative rule: keep housing at 25% of your net (take-home) income. On $4,200 take-home, that's $1,050/month. That's the number that won't keep you up at night.

Don't Forget the Hidden Costs

Your mortgage payment is just the beginning. Here's what actually hits your wallet:

On a $350,000 home, that's an extra $500–$1,200/month on top of your mortgage payment. Plan for it.

The Down Payment Reality

20% down is the gold standard — it eliminates PMI and gets you better rates. But on a $350,000 house, that's $70,000 cash. For many buyers, especially first-timers, that's years of saving.

The good news: FHA loans require as little as 3.5% down. Some conventional loans go as low as 3%. The trade-off? Higher monthly payments, PMI, and less equity from day one.

Rule of thumb: Don't buy until you have at least 10% down PLUS 3–6 months of expenses in emergency savings. Emptying your savings for a down payment leaves you one HVAC failure away from disaster.

Use the Calculator

Our mortgage calculator factors in home price, down payment, interest rate, loan term, property taxes, and insurance. Play with the numbers. See what $1,200/month actually buys you at 6.5% vs. 7.5%.

Then use our debt-to-income calculator to see how that mortgage payment affects your overall financial picture.

The Bottom Line

The house you can afford and the house you want are rarely the same number. That's okay. Buying too much house is the fastest way to turn the American Dream into a financial nightmare.

Start with 25% of net income for total housing costs. Factor in every hidden expense. Keep your emergency fund intact. And remember: you can always upgrade later. You can't undo being house-poor.