How Much House Can You Actually Afford? The Real Numbers Behind the 28% Rule
Lenders will approve you for a loan amount that maximizes their interest income. The question "how much house can I afford?" and "how much will a lender give me?" have different answers — and confusing the two is how people become house-poor. Here's the complete framework for calculating your actual comfortable housing budget.
The 28/36 rule — and why it's not enough
The classic guideline: spend no more than 28% of gross income on housing (PITI — principal, interest, taxes, insurance) and no more than 36% on all debt payments combined. This is a starting point, not a complete answer. Two problems:
- It uses gross income. Your actual take-home pay determines cash flow. High earners in high-tax states (CA, NY) might pay 40%+ effective tax rates — meaning 28% of gross is actually 47% of take-home.
- It excludes ongoing ownership costs: maintenance, HOA, utilities differential, and for <20% down — PMI.
Full housing cost calculation: beyond PITI
| Cost Component | How to Estimate | Example ($500K Home) |
|---|---|---|
| Principal + Interest | Mortgage payment on your loan amount and rate | $2,864/mo (6.8%, 30yr, 10% down) |
| Property taxes | Effective rate × home value ÷ 12 | $625/mo (1.5% rate) |
| Homeowner's insurance | ~0.5–1% of home value ÷ 12 | $250/mo |
| PMI (if <20% down) | ~0.5–1.5% of loan ÷ 12 | $225/mo (0.6% × $450K loan) |
| HOA (if applicable) | Community-specific | $0–$800/mo |
| Maintenance reserve | 1–2% of home value ÷ 12 | $417–$833/mo |
| Total true monthly cost | $4,381–$5,597/mo |
That $500,000 home isn't a $2,864/mo payment. It's a $4,400–$5,600/month housing cost. To keep that at 28% of gross income, you'd need to earn $190,000–$240,000/year.
What different incomes actually buy
| Gross Income | 28% Front-End Budget | After Full Cost (inc. maintenance) | Comfortable Home Price |
|---|---|---|---|
| $60,000 | $1,400/mo | $1,050/mo for P+I | ~$160,000 |
| $80,000 | $1,867/mo | $1,400/mo for P+I | ~$215,000 |
| $100,000 | $2,333/mo | $1,750/mo for P+I | ~$270,000 |
| $130,000 | $3,033/mo | $2,275/mo for P+I | ~$350,000 |
| $180,000 | $4,200/mo | $3,150/mo for P+I | ~$485,000 |
Assumes 6.8% 30yr rate, 20% down, 1.5% property tax, 0.75% insurance, 1.25% annual maintenance reserve. Your rate, tax, and PMI will vary.
The maintenance budget is the most skipped item — and the most expensive mistake. A $400,000 home at 1.5% maintenance reserve = $6,000/year saved for repairs. Roof replacement: $10,000–$25,000. HVAC: $5,000–$12,000. Water heater: $1,000–$3,000. First-time buyers who skip the maintenance reserve become the ones posting on Reddit about being unable to afford unexpected repairs 2 years in. Budget it before you buy.
Calculate your full mortgage cost
Our Mortgage Calculator shows full PITI + PMI for any home price and down payment — plus how extra principal payments reduce total interest.
Open Mortgage Calculator →Cite this article
Randive, A. (2027). How Much House Can You Actually Afford? The Real Numbers Behind the 28% Rule. DecisionsCalc. https://decisionscalc.com/articles/how-much-house-can-you-afford/