How Much House Can I Afford on My Salary?

Before falling in love with a property, it is essential to know your budget ceiling. Buying more house than you can comfortably afford is one of the most common financial mistakes — and one of the most damaging. Here are the frameworks lenders and financial planners use to determine affordability.

The 28/36 Rule

The standard affordability guideline used by most US lenders is the 28/36 rule:

• Your monthly housing costs (mortgage, property tax, insurance) should not exceed 28% of gross monthly income
• Your total debt payments (housing + car loans + student loans + credit cards) should not exceed 36% of gross monthly income

What This Means in Practice

Annual Salary	Max Monthly Housing (28%)	Approx. Home Price (7% rate, 20% down, 30yr)
$50,000	$1,167	~$165,000
$75,000	$1,750	~$245,000
$100,000	$2,333	~$330,000
$150,000	$3,500	~$495,000

The Down Payment Factor

Your down payment directly affects your monthly payment and whether you pay Private Mortgage Insurance (PMI). In the USA, putting down less than 20% triggers PMI, typically 0.5–1.5% of the loan amount per year, adding $100–$300/month to your costs.

• 5% down on $300,000: loan = $285,000, monthly P&I ~$1,897 + PMI ~$150 = $2,047
• 20% down on $300,000: loan = $240,000, monthly P&I ~$1,597, no PMI

UK: Mortgage Multiples

UK lenders typically use income multiples rather than percentage rules. Most lenders will offer 4 to 4.5 times your annual income, with some offering 5–5.5 times for high earners. On a joint income of £80,000, you could typically borrow £320,000–£360,000.

South Africa: Bond Affordability

South African banks generally apply a 30% of gross income rule for bond repayments. At prime rate (~11.75% in 2024), a R1,500,000 bond costs approximately R16,500/month. You need a gross income of around R55,000/month to qualify.

Hidden Costs to Budget For

First-time buyers consistently underestimate the ongoing costs of ownership:

• Maintenance: budget 1% of home value per year (older homes, budget 1.5–2%)
• Property taxes: 0.5–2.5% of home value annually depending on location
• Homeowner’s insurance: $1,000–$2,500/year in the USA
• HOA fees (if applicable): $200–$600/month in many developments

The Most Important Rule

Lender pre-approval tells you the maximum you can borrow — not the maximum you should borrow. Just because a bank will lend you $450,000 does not mean that is a wise use of your income. Always leave room for other financial goals: retirement savings, emergency fund, and quality of life. A home that stretches your budget to breaking point is a financial trap, not an asset.

Worked Example: A $120,000 Household Income

A two-earner household making $120,000 combined ($10,000/month gross) walks into a lender with $48,000 saved, $440 in monthly minimum debt (one car loan), and 760 average credit scores. The 28% rule says monthly PITI shouldn't exceed $2,800. The 36% rule caps total debt service at $3,600, leaving roughly $3,160 for housing after the car loan. The conservative number is $2,800.

Now plug into the maths at a 7.1% 30-year fixed rate (Freddie Mac PMMS January 2026 weekly average). The down payment of $48,000 covers 12% of a $400,000 purchase, triggering PMI of about $120/month. Estimated property tax at 1.2% adds $400/month, homeowner's insurance $115/month. The loan principal and interest on $352,000 is $2,367. Total PITI: $3,002. That's $202 over the 28% rule. Either drop the price to $370,000, or wait six months and add $15,000 to the down payment to bring PMI down and the principal lower.

Most first-time buyers skip the long maintenance projection. On a $400,000 house, 1% maintenance reserve is $4,000/year, or $333/month set aside, not spent. Add closing costs at 2–4% of purchase price ($8,000–$16,000), moving expenses, immediate furnishing (typically $5,000–$15,000), and the realistic cash buffer to enter ownership safely is $48,000 + $20,000 = closer to $68,000. Many sales fail because buyers funded only the down payment.

Common Mistakes Buyers Make

• Borrowing to the bank's maximum. Pre-approval is what they're willing to lend. What you should borrow is usually 70–85% of that figure.
• Forgetting taxes and insurance in the monthly maths. A $1,800 P&I payment becomes $2,400 PITI once escrows hit. Always run the full PITI number.
• Skipping the maintenance reserve. Roofs, water heaters, HVAC systems, and exterior paint don't appear on the closing disclosure. Budget 1% of home value per year minimum.
• Ignoring the rate environment. A 1% rate increase shifts buying power by roughly 10%. Get pre-approved with current rates, not last year's.
• Buying for a phase of life you've left. The "we'll have kids" four-bedroom when the kids might never come is a five-figure annual cost in extra mortgage, utilities, and tax.

Regional Differences: USA, UK, South Africa

USA. The 28/36 rule is the canonical lender benchmark, alongside FHFA conforming loan limits ($766,550 baseline in 2024, higher in high-cost areas). Property taxes vary wildly — Texas runs 1.6–2.5%, California 0.7–1.2%, but California's Prop 13 limits annual reassessments. PMI is triggered below 20% down on conventional loans, removable at 78% LTV under HPA. FHA loans permit 3.5% down but include lifetime MIP.

UK. Affordability is set by lender stress tests under FCA MMR rules, typically checking whether you could afford payments at SVR + 1%. Income multiples sit at 4.5x for most lenders, 5.5x with strong income from Halifax, Nationwide, Barclays. Stamp Duty (SDLT) is a major upfront cost — first-time buyers pay zero on purchases up to £425,000 (2024-25 rates per HMRC). Help to Buy is closed for new applications; the Lifetime ISA (£4,000/year contribution, 25% government bonus) is the main first-time buyer assistance.

South Africa. Banks apply a 30% gross-income affordability test with prime + 1% used for stress checks. At prime rate of 11.75% (early 2025, SARB), borrowing R1.5m on a 20-year bond costs around R16,260/month. Transfer duty kicks in above R1.1m (zero below) per SARS 2024-25 tables, plus bond registration, conveyancing, and FICA verification fees easily totalling R60,000–R90,000 on a R1.5m purchase. First-time buyers under R3.5m can apply for the FLISP government subsidy via the Department of Human Settlements.

Actionable Next Steps

1. Use the Mortgage Calculator to model full PITI at current rates, not just principal and interest.
2. Get pre-approved with two lenders. The rate difference can be 0.25–0.5%, worth $20,000+ over a 30-year term.
3. Build your real cash-to-close: down payment + closing costs + moving + reserves. Aim for 30% more than the down payment alone.
4. Stress-test the payment at +2% rates. If you couldn't comfortably afford it, you're borrowing too much.
5. Keep your savings rate at 15%+ of gross income through the buying process. Don't drain retirement to fund the house.

FAQ

How much higher is the actual cost of homeownership than the mortgage payment? Typically 35–50% higher once property tax, insurance, maintenance, and utilities are included. A $2,000 P&I payment usually represents about $3,000 of true monthly housing cost on a typical US single-family home.

Should I include my partner's income on the application? If both incomes are stable and credit scores are similar, yes — it raises borrowing capacity. If one partner has poor credit, applying solo with the better-credit partner can secure a better rate at lower borrowing capacity. Joint income with a co-borrower vs single-borrower assessment varies by lender.

What credit score do I need? Conventional US mortgages typically need 620+, FHA loans 580+. UK lenders work from full credit files rather than single scores. SA banks use the credit bureau record plus ITC reports — most require a clean record for the past 12 months minimum.

How do student loans affect affordability? US lenders count the actual monthly payment against the 36% back-end ratio, even on income-driven repayment plans. UK lenders include the Plan 1/Plan 2 payment from payslips. Higher student-loan payments directly reduce mortgage capacity.

Sources and Methodology

The 28/36 rule originates with Fannie Mae and Freddie Mac selling guides as the standard underwriting ratios. Current US mortgage rates come from Freddie Mac PMMS. UK lender stress-test rules follow FCA Mortgage Market Review (MMR) and PRA SS3/16. SA affordability tests reference the National Credit Act and SARB prime rate. Property tax rates by US state are from the Tax Foundation 2024 report.