The Two Main Affordability Rules
In the United States, lenders and financial advisors use two widely accepted guidelines to determine how much mortgage is manageable:
Here's how to apply it step by step:
- Step 1: Take your annual gross income and divide by 12 to get monthly gross income
- Step 2: Multiply by 0.28 — this is your maximum monthly housing payment
- Step 3: Subtract monthly property tax and insurance estimates to find your maximum P&I payment
- Step 4: Use our mortgage calculator to find what loan amount that payment corresponds to at current rates
For example, on a $90,000 gross annual salary:
- Monthly gross income: $7,500
- 28% rule: max monthly housing cost = $2,100
- Subtract $300/mo for taxes + insurance = max P&I of $1,800
- At 6.75% for 30 years, $1,800/mo P&I supports a loan of roughly $275,000
- With 10% down ($30,000), that means a home price up to roughly $305,000
Canada: The GDS and TDS Rules
Canadian lenders use two official ratios set by federal regulators — and these are stricter than the US 28/36 rule, particularly for insured mortgages:
| Ratio | What It Includes | Maximum Allowed |
|---|---|---|
| GDS (Gross Debt Service) |
Mortgage P&I + property taxes + heating costs + 50% of condo fees | 39% of gross income |
| TDS (Total Debt Service) |
Everything in GDS + all other debt payments (car, student, credit cards) | 44% of gross income |
Canadian lenders will not approve you if either ratio exceeds these limits. In practice, most financial advisors recommend keeping your GDS under 32% to give yourself breathing room.
Real Salary Examples: What Can You Afford?
Using the 28% rule (US) and assuming a 6.75% rate, 30-year term, 10% down payment, and $350/month in taxes and insurance:
| Annual Salary | Max Monthly Payment (28%) | Max Loan Amount | Max Home Price (10% down) |
|---|---|---|---|
| $50,000 | $1,167 | $131,000 | ~$145,000 |
| $60,000 | $1,400 | $158,000 | ~$175,000 |
| $75,000 | $1,750 | $198,000 | ~$220,000 |
| $90,000 | $2,100 | $238,000 | ~$264,000 |
| $100,000 | $2,333 | $265,000 | ~$294,000 |
| $120,000 | $2,800 | $318,000 | ~$353,000 |
| $150,000 | $3,500 | $398,000 | ~$442,000 |
| $200,000 | $4,667 | $531,000 | ~$590,000 |
These are guidelines using the 28% rule at 6.75%. Your actual approval amount depends on credit score, existing debts, lender policies, and the specific property. Use our calculator to get precise numbers for your situation.
The Hidden Costs Most Buyers Forget
Your mortgage payment is only part of the true monthly cost of homeownership. Many first-time buyers are blindsided by these additional expenses — and failing to account for them is one of the biggest financial mistakes a new homeowner can make.
| Cost | Typical Amount | Notes |
|---|---|---|
| Property Tax | 1–2% of home value/year | On a $400K home: $333–$667/mo |
| Home Insurance | $1,000–$2,500/year | Higher in flood/fire risk areas |
| PMI / CMHC | $100–$500/mo (US) or upfront (Canada) | Required if down payment < 20% |
| Maintenance & Repairs | 1–2% of home value/year | Budget $3,000–$8,000/yr on a $400K home |
| Utilities | $200–$500/mo | Higher in older or larger homes |
| HOA / Condo Fees | $200–$800/mo | Varies widely by building/community |
| Land Transfer Tax | 0.5–2.5% of price (one-time) | Canada: applies in most provinces. Some US states have this too. |
| Total Extra Costs | Often $1,000–$2,000+/month beyond the mortgage payment | |
The Mortgage Stress Test (US & Canada)
Both the US and Canada have stress tests designed to make sure you can afford your mortgage even if rates rise.
Canada: The federal stress test requires lenders to qualify you at the higher of your actual mortgage rate + 2%, or the Bank of Canada's benchmark qualifying rate (currently 5.25%). This means if you're getting a 6.5% mortgage, the bank qualifies you as if the rate were 8.5%. This significantly reduces your maximum approved amount.
US: The Dodd-Frank Act requires lenders to verify your ability to repay. While there's no single "stress test" rate like Canada's, lenders factor in worst-case scenarios for ARMs and apply a debt-to-income cap. Conventional loans typically require a DTI under 45–50%.
The practical impact in Canada is significant. If the stress test rate is 8.5% but the actual rate is 6.5%, you may qualify for roughly 15–20% less home than the payment alone would suggest.
Why You Should Borrow Less Than the Maximum
This is the most important advice in this entire article: just because a bank approves you for $450,000 doesn't mean you should spend $450,000.
Here's why borrowing conservatively makes sense:
- Job security isn't guaranteed. A comfortable payment at 28% of income becomes a crisis payment at 40% if your income drops temporarily.
- Interest rates can rise. If you have a variable rate or your mortgage renews in 3–5 years, your payment could increase substantially.
- Life happens. Kids, health issues, car replacements, aging parents — your expenses will grow in ways you can't predict at purchase time.
- Quality of life matters. Being "house poor" — owning a nice home but having no money left for anything else — is a miserable way to live. Many people who regret buying, regret buying too much, not buying at all.
A practical target many financial advisors recommend: aim for a total housing cost (mortgage + taxes + insurance + maintenance) of no more than 25% of your take-home pay — not gross income. This is more conservative than the 28% rule and gives you much more financial flexibility.
Next Steps: From Budget to Pre-Approval
Once you know your comfortable price range, here's how to move forward:
- Check your credit score. In the US, get a free report at annualcreditreport.com. In Canada, check with Equifax or TransUnion. Dispute any errors — they're more common than you'd think.
- Calculate your debt-to-income ratio. Add up all monthly debt payments, divide by gross monthly income. Aim for under 36% (US) or under 44% TDS (Canada) before applying.
- Save for closing costs separately. Budget 2–5% of the home price for closing costs on top of your down payment. This is a common oversight that delays closings.
- Get pre-approved, not just pre-qualified. Pre-approval involves a real credit check and income verification — it's what sellers and their agents take seriously.
- Shop at least 3 lenders. Rates vary more than most buyers realize. Even 0.25% difference on a $350,000 loan saves over $18,000 over 30 years.