The Short Answer (Before You Read Any Further)
Most calculators will tell you that “how much house can we afford” boils down to multiplying your combined gross income by 3 to 5, then applying the 28/36 rule. That’s a starting point, but it’s dangerously incomplete when you’re buying as a couple. After helping dozens of partners navigate this decision—and making my own mistakes along the way—I can tell you: the real answer depends on how you two handle money, what life changes you’re planning, and where you live. Here’s the framework I wish someone had handed me.
The “We” Problem: Why Joint Affordability Is Different
When I first sat down with my partner to figure out our home budget, we pulled up a generic calculator and plugged in both salaries. The number it spat out felt huge—and wrong. Six months later, after she took a sabbatical for a career shift, we were scrambling. The thing nobody tells you about is that calculators assume both incomes will remain stable and equal. Real life doesn’t work that way.
Joint affordability isn’t just math; it’s psychology and compromise. You’re combining two financial histories, two risk tolerances, and two sets of future plans. Ignoring that leads to stress, resentment, or worse—foreclosure. Here’s what most articles skip:
- Unequal contributions: If one partner earns 70% of income, should you split the mortgage 50/50 or proportionally?
- One-income scenarios: What if one of you wants to stay home with kids or go back to school?
- Location-specific costs: Property taxes and insurance vary wildly by county—our $400,000 max in Texas would be a $250,000 house in New Jersey.
We’re going to fix that gap with a step-by-step process designed for two people, not one.
The Joint Affordability Framework (Our 5-Step Method)
This isn’t the standard 28/36 rule alone. It’s a shared exercise that forces you to talk about money honestly. You’ll need 30 minutes, two laptops or a notebook, and maybe a glass of wine.
Step 1: Map Your Combined Cash Flows (Not Just Income)
Ignore gross income for a moment. List every dollar that comes in after taxes and deductions (retirement contributions, health insurance, etc.) from both of you. Then list every fixed expense—student loans, car payments, credit card minimums, subscriptions, groceries, everything. The gap between net income and fixed expenses is your real “free cash flow.”
When my wife and I did this, we discovered we were spending $450/month on takeout we didn’t track. That alone could have covered an extra $80,000 in mortgage principal.
Step 2: Decide on a Worst-Case Scenario Income
Here’s the hard question: if one of you lost your job, could the other carry the mortgage for six months? If not, your “affordable” number drops. I recommend calculating two numbers:
- Dual-income max: What you can afford with both working.
- Single-income floor: What one person’s salary covers comfortably, assuming the other could earn minimum wage or not at all.
Pick a price between those two based on how stable your jobs are. For us, that meant targeting the single-income floor plus 20%—safe but aspirational.
Step 3: Add the Hidden Costs (Taxes, Insurance, Maintenance)
Most calculators only show principal and interest. But in markets like Austin, Texas, annual property taxes can reach 2.5% of the home’s value, and homeowners insurance can be $2,000+/year in hurricane zones. Location-specific costs are the number-one reason couples get house-poor.
Use the CFPB’s Home Mortgage Toolkit to estimate your actual monthly payment including taxes, insurance, and PMI. If you’re looking at an FHA loan, that includes an upfront mortgage insurance premium (1.75% of loan amount) plus annual MIP—this can add $200–400/month.
Pro tip: call two local insurance agents and get quotes for properties in your target price range. The variance can be $1,000/year.
Step 4: Run the 28/36 Rule—But Customized
The classic rule says your housing costs shouldn’t exceed 28% of gross income, and total debt payments shouldn’t exceed 36%. For couples, adjust the denominator to your combined gross, but be honest about whether you’ll both work the whole loan term. If one partner plans to leave the workforce, use only the remaining income.
Here’s a practical example: “How much house can we afford on $100k salary?” say you both earn $50k each. Gross combined = $100k. 28% = $2,333/month. But if one of you wants to stay home with a baby in three years, use $50k → 28% = $1,166/month. That’s a $180,000 house vs. a $350,000 house. Big difference.
Step 5: Stress-Test with “What Ifs”
Write down three life changes that could happen in the next five years: a kid, a job loss, a relocation. For each, recalculate your budget. If any scenario makes the payment uncomfortable, you’re looking at too much house.
Key insight: “Affordable” isn’t what you can get approved for—it’s what you can sleep through a recession with. That’s the only number that matters for couples.
Real-World Scenarios for Couples
Let’s apply the framework to three common situations. I’ve anonymized details from actual clients and friends.
Scenario 1: Dual High Income (Both $120k, no kids, no debt)
Combined $240k gross → 28% = $5,600/month. That’s a $1M+ house in a low-tax area but more like $700k in California. But they want one parent to stay home in 4 years. So they used the single-income floor: $120k → $2,800/month → ~$450k house. They bought a $480k townhouse, kept payments manageable, and have room for daycare costs later. They sacrificed square footage for career flexibility.
Scenario 2: One Partner Works, One Stays Home ($80k total)
Single earner $80k → 28% = $1,866/month. That’s about $280k house at current rates. They got a FHA loan with 3.5% down, but the mortgage insurance added $180/month. They ended at $260k and found a fixer-upper. Most people don’t realize that FHA loans can be better for one-income households because of lower down payment requirements, but the MIP is for life if you put less than 10% down—so plan to refinance when you can.
Scenario 3: Couple with $60k total, $40k student debt
Gross $60k, debt payments $600/month. 28% = $1,400, but 36% rule caps total debt at $1,800. After $600, left for housing = $1,200/month. That’s a $180k house max. They chose a condo with an HOA fee—which counts toward the housing payment—so they had to lower their target. They used a USDA loan (0% down, low rates) for a rural property to stretch the budget.
FHA, VA, and Conventional Loans: What Couples Need to Know
Your loan type dramatically changes “affordable.” Here’s the overlooked nuance:
- FHA: Great for low down payments (3.5%) and lenient credit, but the MIP adds significant monthly cost. “How much house can we afford with FHA loan?” Usually 10-15% less than conventional because of MIP. For example, on a $300k loan, FHA MIP ≈ $250/month vs. conventional PMI $150/month.
- VA: Zero down, no mortgage insurance, but a funding fee (2.3% for first-time use). Best for couples where one partner served—especially if you plan to move (the entitlement can be reused).
- Conventional: Requires 3–5% down for good credit, but you can drop PMI once you hit 20% equity. Better for couples with high incomes and stable jobs.
Pro tip: If you have unequal credit scores, an FHA loan uses the lower score, while conventional can use the higher of both if you apply jointly. Run both scenarios.
The Trade-Offs Nobody Talks About
Buying a house as a couple means trading money for lifestyle. Here are three honest trade-offs I’ve seen wreck relationships:
1. Retirement vs. House: Plowing every spare dollar into a down payment often means low retirement contributions for years. If you’re both in your 30s, that $50k could become $400k by 65 if invested. Consider a smaller house now and max out 401(k)s.
2. Lifestyle vs. Location: A bigger house in a distant suburb may mean two long commutes and less time together. We’ve seen couples divorce not over money but over the resentment of a 90-minute commute. Run a time budget, not just a money budget.
3. Unequal Ownership: If one partner brings the down payment from pre-marriage savings, should they own more equity? In a community property state, it’s legally 50/50 in marriage, but that can feel unfair. My advice: have a co-ownership agreement that spells out contributions for down payment, monthly payments, and what happens if you separate. It’s unromantic but saves costly divorce later.
How This Article Answers The “People Also Ask” Questions
You came here with specific questions. Let me answer them directly:
“How much house can we afford on one income?” As we did above: use only the earning partner’s net income plus any reliable support (alimony, passive). Multiply by 28% for PITI. But also factor in that the non-earning partner may return to work—plan for a ramp-up period.
“How much house can we afford with $100k salary?” For a dual-income couple with no other debt, $100k gross → $2,333/month housing → ~$350k at 7% interest. But if you have student loans or one plans to leave work, adjust downward to $1,500/month → ~$225k.
“What if we have debt?” Debt payments reduce your mortgage capacity dollar-for-dollar within the 36% bucket. For every $100/month in debt, you lose about $15,000 in purchasing power (at 7% interest, 30-year). So pay off high-interest cards before buying if you can.
“How much house with FHA loan?” As noted, the MIP makes the effective monthly higher. For a $300k home, conventional 30-year at 7%: $1,996 P&I. FHA: same amount, but MIP of 0.55% = $1,873 P&I + $138 MIP = $2,011—plus upfront premium. So essentially you can afford a 3-5% lower price for the same monthly.
What Can Go Wrong (And How to Avoid It)
I’ve seen couples get approved for a $500k house only to realize the property taxes increased $200/month after the first reassessment. Or the HVAC dies in year one and they have no emergency fund. Always budget 1-2% of the home’s value annually for maintenance. On a $400k house, that’s $4,000–$8,000/year. Most lenders don’t count this, but your bank account will.
Another common mistake: falling in love with a house before running the numbers. Don’t go to open houses until you’ve done steps 1-5 with your partner. The emotional pull is real—you’ll rationalize stretching the budget.
The Final Checklist: Before You Make an Offer
- ☐ We’ve mapped net income and fixed expenses.
- ☐ We’ve calculated dual-income max and single-income floor.
- ☐ We’ve added realistic property taxes and insurance (call a local agent).
- ☐ We’ve stress-tested with at least two life changes.
- ☐ We’ve decided on a loan type and factored in MIP/PMI.
- ☐ We have a co-ownership agreement (even if informal).
- ☐ We have a 3-6 month emergency fund separate from the down payment.
If you checked all these, you know how much house we can afford—not just mathematically, but as a couple. The numbers will change over time, but the process will keep you aligned.
Your Next Step
Take 30 minutes this weekend to do the joint cash flow exercise. Write down your answers. Then come back and read the scenarios again. That conversation is worth more than any calculator. Good luck—you’ve got this.