First Home Budget Planner

Back to our main guide: The Ultimate First-Time Home Buyer Checklist.

How Much House Can You Actually Afford?

One of the biggest mistakes first-time home buyers make is relying entirely on their lender to tell them how much house they can afford. Lenders calculate your maximum borrowing power based on gross income and risk models, not on your personal lifestyle, retirement goals, or childcare costs. If you borrow the absolute maximum your lender approves you for, you risk becoming "house poor"—meaning a disproportionate amount of your income goes toward housing, leaving little left for everything else.

To determine your true budget, you need to understand how lenders view your finances and then apply those metrics to your own comfort level.

The Golden Rule of Mortgages: The 28/36 Rule

Most financial advisors and conservative mortgage lenders use the 28/36 Rule to calculate housing affordability. This rule states that:

• The 28% Rule (Front-End Ratio): No more than 28% of your gross monthly income (your income before taxes are taken out) should go toward your total housing expenses. "Total housing expenses" means PITI: Principal, Interest, Property Taxes, and Homeowners Insurance (plus HOA fees if applicable).
• The 36% Rule (Back-End Ratio / DTI): No more than 36% of your gross monthly income should go toward all your debt obligations combined. This includes your new housing payment plus your existing auto loans, student loans, minimum credit card payments, and personal loans.

Our First Home Budget Planner above uses the 36% back-end DTI ratio (Debt-to-Income) as the primary limiting factor, as it is the most common hurdle for modern buyers who often have existing student or auto debt.

The PITI Breakdown

When you calculate your monthly housing budget, you must look beyond just the principal and interest of the loan itself. The acronym PITI represents the four components of a standard mortgage payment:

1. Principal: The portion of your payment that goes toward paying down the actual balance of the loan.
2. Interest: The fee the lender charges you for borrowing the money. In the early years of a 30-year mortgage, the vast majority of your payment goes toward interest.
3. Taxes: Local property taxes. Lenders usually divide your annual property tax bill by 12 and collect it monthly, holding it in an escrow account to pay the government on your behalf when it's due.
4. Insurance: Homeowners insurance (which protects against fire, theft, etc.) and Mortgage Insurance (PMI or CMHC) if your down payment is less than 20%. Like taxes, this is usually collected monthly into an escrow account.

If you fail to account for taxes and insurance, you will drastically overestimate how much house you can afford. Depending on where you live, high property taxes can easily add hundreds of dollars to your monthly payment.

Hidden Costs of Homeownership to Budget For

Beyond your PITI payment, owning a home comes with ongoing costs that renters don't have to worry about. When setting your final budget, ensure you leave room for:

• Maintenance and Repairs: The general rule of thumb is to budget 1% to 2% of your home's total value per year for maintenance. If you buy a $400,000 house, you should save $4,000 to $8,000 annually for things like HVAC servicing, roof repairs, and plumbing issues.
• Utilities: Houses are usually larger than apartments, meaning higher heating, cooling, and electricity bills. You will also likely be responsible for water, sewer, and trash collection fees.
• Furnishing and Equipment: A bigger space requires more furniture. You'll also need to purchase a lawnmower, snow shovel, ladders, and various tools.

Before locking in a purchase price, practice "paying" your new mortgage. If your current rent is $1,500 and your estimated new mortgage is $2,200, put that $700 difference into a savings account every month for a few months. If your budget feels painfully tight, you know you need to look at less expensive homes.