How to Calculate How Much House You Can Actually Afford

How to Calculate How Much House You Can Actually Afford

A lender will tell you the maximum you can borrow. That number is often dangerously high. Just because you qualify for a $500,000 mortgage does not mean a $500,000 mortgage fits your life. The gap between what you can borrow and what you should borrow is where financial stress lives.

Here is how to figure out what you can actually afford, not what a formula says you qualify for.

Start with the Lender's Math

Lenders use your gross income and debts to calculate affordability. The standard rule is that your total housing payment should not exceed 28 percent of gross monthly income (front-end ratio) and your total debts including housing should not exceed 36 to 43 percent (back-end ratio).

If you earn $8,000 per month gross, the 28 percent rule suggests a maximum housing payment of $2,240. That includes principal, interest, taxes, insurance, and any HOA or mortgage insurance. Working backward from that payment, your purchase price depends on the interest rate, property taxes, and insurance in your area.

This formula is a starting point, not an answer. It ignores almost everything that makes your financial life unique.

What Lenders Do Not Consider

The DTI calculation uses gross income, but you live on net income. If 30 percent of your gross goes to federal, state, and payroll taxes, and another 5 to 10 percent goes to retirement contributions, you are working with significantly less than the gross number the lender uses.

Lenders also do not factor in:

• Childcare costs (often $1,000 to $2,500 per month per child)
• Healthcare premiums and out-of-pocket medical costs
• Groceries and household expenses
• Transportation costs beyond a car payment
• Saving for retirement, college funds, or emergencies
• Lifestyle spending: travel, dining, hobbies, subscriptions
• Future expenses like a growing family or career transition

A household earning $120,000 with two kids in daycare has a fundamentally different budget than a household earning $120,000 with no dependents, but the lender treats them nearly the same.

The Net Income Approach

A more realistic method is to base your housing budget on take-home pay. Many financial planners suggest keeping your total housing cost at or below 25 to 30 percent of your net monthly income. This is more conservative than the lender's formula, and that is the point.

If your household take-home is $7,200 per month, aim for a total housing payment of $1,800 to $2,160. That feels tighter than the lender's number, but it leaves room for the rest of your financial life.

Do Not Forget the Hidden Costs of Homeownership

Your mortgage payment is not your total housing cost. Budget for:

Property taxes: These vary dramatically by location. A $400,000 home might have taxes of $3,000 per year in one state and $10,000 in another. Research actual tax rates for the areas you are considering.

Homeowners insurance: Typically $1,200 to $3,000 per year, but much higher in disaster-prone areas. Get actual quotes for the properties you are seriously considering.

Maintenance and repairs: Plan for 1 to 2 percent of the home's value annually. On a $400,000 home, that is $4,000 to $8,000 per year. Older homes will trend toward the higher end. This is not optional spending. Roofs fail, furnaces die, and plumbing leaks. It is a matter of when, not if.

HOA fees: If applicable, these can range from $100 to $500 or more per month. They are part of your housing cost and factor into your DTI.

Utilities: Homeowner utilities are typically higher than renter utilities. A larger space with separate heating and cooling costs more to operate. Ask the seller or utility company for average monthly costs.

The Lifestyle Budget Test

Before you commit to a price range, run this exercise. Write down your monthly take-home income. Subtract your estimated total housing payment (mortgage, taxes, insurance, HOA, estimated maintenance, utilities). Subtract all fixed expenses (childcare, car payments, student loans, insurance premiums). Subtract savings commitments (retirement contributions, emergency fund, other goals).

What is left is your discretionary budget for groceries, dining, entertainment, travel, clothing, and everything else. Is that number realistic for how you want to live?

If the remaining amount feels uncomfortably tight, your target home price is too high. Reduce it until the numbers leave breathing room. Being house-poor, where your home consumes so much of your income that you cannot enjoy it, is one of the most common financial regrets homeowners report.

The Stress Test

Run two additional scenarios:

What if one income drops? If you are a dual-income household, could you cover the mortgage on one income for six months? Job loss, medical leave, and parental leave happen. Your housing payment should not put you in crisis if one income temporarily disappears.

What if expenses increase? Property taxes go up. Insurance premiums rise. Interest rates affect your home equity line of credit. Build a cushion so that a 10 to 15 percent increase in housing-related costs does not break your budget.

Working Backward from Your Comfort Zone

Instead of starting with a home price and checking if you qualify, start with a monthly payment that feels comfortable and work backward to find your price range.

If $2,000 per month is your all-in housing comfort zone and you estimate $400 for taxes, $150 for insurance, and $100 for PMI, you have $1,350 for principal and interest. At a 6.5 percent rate on a 30-year term, that supports a loan of about $214,000. Add your down payment, and that is your target purchase price.

This approach keeps your financial life in balance instead of stretching it to the breaking point.

SOMA helps you calculate a realistic home budget based on your full financial picture, not just what you technically qualify for. Find your comfortable price range at heysoma.ai.