How Much House Can I Afford? A Practical Framework

“How much house can I afford?” is often answered with a multiple of income or a lender qualification number. Those can be useful reference points, but neither is the same thing as a household budget.

A better affordability test asks:

What purchase price can the household carry while still paying every other obligation, maintaining cash reserves and making progress on the rest of its goals?

Start with the monthly payment—but do not stop there

The mortgage principal-and-interest payment is only one part of homeownership.

A realistic monthly housing model can include:

• principal and interest;
• property taxes;
• homeowners insurance;
• HOA or condo fees;
• mortgage insurance when applicable;
• utilities that change with the property;
• a maintenance/repair reserve.

A $3,500 mortgage payment can easily become a $4,500+ housing obligation once the rest is added.

A worked example

Assume a household earns $180,000 per year and has $800 of recurring monthly non-housing debt.

They are considering a home with:

• $700,000 purchase price;
• 20% down;
• $560,000 mortgage;
• 6.5% 30-year fixed rate;
• $12,000 annual property tax;
• $2,400 annual homeowners insurance;
• $250 monthly HOA.

The principal-and-interest payment on the loan is only the starting point. Add roughly $1,000 per month of property tax, $200 of insurance and $250 of HOA before maintenance or utilities.

The question is not whether a lender could approve it. The question is whether that all-in housing cost leaves enough monthly flexibility for retirement, child care, debt, travel, repairs and ordinary life.

Down payment is not your only closing cash

A buyer can have enough for a 20% down payment and still be financially unprepared to close.

Cash can also be needed for:

• lender/origination charges;
• title and settlement costs;
• appraisal and inspections;
• prepaid taxes and insurance;
• transfer or recording taxes where applicable;
• moving costs;
• immediate repairs or furnishings.

That is why MFA separates Affordability from Closing Costs instead of assuming every available dollar should become the down payment.

Keep a post-closing reserve

A home purchase converts liquid cash into home equity and transaction costs.

If someone has $150,000 in cash and uses $145,000 to close, the household may technically have bought the home but created a new liquidity problem.

Before selecting a down payment, decide how much cash should remain after closing for emergencies, repairs and near-term obligations.

Test the rate, not just the price

Affordability can change materially with mortgage rates.

The same $560,000 mortgage has a very different payment at 4%, 6% and 7%. If a purchase is barely comfortable under today's rate, do not rely on a future refinance to make the budget work.

A refinance may never arrive at the rate, time or cost you hope for.

Instead, test:

• current rate;
• one point higher;
• one point lower.

If the plan is fragile under a modest rate or cost change, that is useful information.

Debt-to-income ratios are not personal spending plans

Lenders use debt-to-income measures as part of underwriting, but a household can satisfy underwriting and still feel stretched.

DTI may not fully capture:

• private-school tuition;
• expensive child care;
• support for parents;
• large travel commitments;
• aggressive retirement saving;
• medical costs;
• home-maintenance preferences;
• irregular but predictable expenses.

Your budget should.

Multi-property households need a different view

Someone may rent a primary home while owning a rental property. Another household may own a primary home and a vacation home. An affordability calculation for the next property should not erase the existing ones.

MFA's Money Plan now keeps each place separate, including rent paid, rent received, property value and mortgage assumptions.

For a rental property, do not simply subtract expected rent from the new mortgage and call the difference affordable. Vacancy, repairs, management, taxes and other property expenses matter too.

Common affordability mistakes

Using the lender maximum as the target. Approval is a credit decision, not a lifestyle recommendation.

Spending all available cash at closing. The home will eventually need something.

Ignoring HOA and taxes. They can rival a meaningful portion of principal-and-interest cost.

Assuming taxes and insurance never change. They can increase materially.

Counting bonuses as guaranteed salary. Variable compensation deserves a stress case.

Depending on a future refinance. Model today's payment as if you may have to keep it.

A better home-buying checklist

Before deciding on a price, write down:

1. stable household income;
2. recurring monthly debts;
3. down payment you are willing to use;
4. cash you want to keep after closing;
5. mortgage rate and term;
6. property taxes;
7. insurance;
8. HOA/condo fees;
9. maintenance reserve;
10. remaining monthly room for the rest of life.

Then run at least three purchase-price scenarios rather than solving for one maximum number.

A home is affordable when the whole household plan still works after you own it, not merely when a mortgage calculator produces a payment you can technically make.