Most first-time buyers spend weeks browsing listings before they’ve looked at a single number that actually determines what they can buy. They fall in love with homes that are $80,000 outside their real budget, get disappointed at pre-approval, or — worse — get to underwriting and discover a debt or credit issue that kills the deal entirely.
The fix is simple but most buyers skip it: know your numbers before you start looking. Seven specific numbers determine your entire mortgage outcome — what you can borrow, which loan programs you qualify for, what rate you’ll be offered, and whether any lender will say yes at all.
This checklist walks through each of the seven numbers, explains why it matters, and tells you exactly what a good, acceptable, and problematic figure looks like — so you can assess where you stand before you ever talk to a lender.
Why You Need These Numbers Before You Start Looking
There’s a natural tendency to start the homebuying process by browsing Zillow or Realtor.com — it’s exciting, it’s visual, and it feels like progress. The problem is that browsing without knowing your numbers leads to one of two outcomes: you anchor on a price range you can’t actually qualify for, or you miss opportunities in a range that’s actually well within reach.
Lenders don’t care which neighbourhood you love. They care about seven specific numbers, and those numbers determine your outcome before a single offer is written. Getting your numbers right before you start house hunting means you walk into every showing knowing exactly what you can offer, and you walk into every lender conversation with zero surprises.
The seven numbers below cover everything a lender will examine. Know all seven and you’ll have a clearer picture of your mortgage readiness than most buyers ever get — even those who’ve already applied.
Number 1: Your Credit Score
Your credit score is the first filter lenders apply. Before they look at your income, your debt, or your down payment — they look at your score. It determines which loan programs are available to you, what interest rate you’ll be offered, and in some cases whether you’ll be approved at all.
The score that matters for mortgage purposes is your FICO score — specifically the middle of your three bureau scores (Equifax, Experian, TransUnion). If you’re applying jointly, lenders typically use the lower of the two borrowers’ middle scores.
| Score Range | Rating | Loan Access | Rate Impact |
|---|---|---|---|
| 740+ | Excellent | All programs, best terms | Lowest available rates |
| 700–739 | Good | All conventional programs | Near-best rates |
| 660–699 | Fair | Conventional with conditions | Slightly higher rates |
| 620–659 | Borderline | FHA preferred, conventional possible | Noticeably higher rates |
| 580–619 | Low | FHA only (3.5% down) | High rates, limited options |
| Below 580 | Very low | FHA with 10% down only | Very high rates or denial |
The rate difference between a 620 and a 740 score on a $280,000 loan can be 1–1.5% — which translates to $50,000–$75,000 in extra interest over 30 years. If your score is below 700, a 6–12 month improvement plan before applying is worth more than almost any other financial move you can make.
Number 2: Your Gross Monthly Income
Every ratio lenders calculate uses your gross monthly income — your pre-tax earnings — as the denominator. This is not your take-home pay, not your net income after deductions. It’s what you earn before the government takes its share.
For a salaried employee, this is simple: divide your annual salary by 12. For hourly workers, multiply hourly rate × average weekly hours × 52 ÷ 12. The complexity comes with additional income sources — overtime, bonuses, side income, rental income, alimony received. Lenders have specific rules about each:
- Base salary: Counts in full immediately ✅
- Overtime and bonuses: Must be documented for 2 years and likely to continue ✅
- Self-employment income: 2 years of tax returns required, typically averaged ✅
- Side/gig income: 2 years of tax returns, must show consistency ✅
- Rental income: 75% of gross rental income typically counts ✅
- New job income: Usually counts if same field and no probation period ⚠️
If you have variable income, your qualifying income may be lower than what you actually earn in a good month. Know what lenders will count before you calculate your budget.
Number 3: Your Monthly Debt Payments
This is the number most first-time buyers underestimate. Add up every recurring monthly debt obligation you have — not your spending, not your subscriptions, but your actual debt payments.
What to include:
- Car loans and auto leases — full monthly payment
- Student loan minimum payments (even if in deferment — lenders impute a payment)
- Credit card minimum payments shown on your statements
- Personal loans
- Child support or alimony you pay
- Any co-signed loan where you’re liable
What NOT to include:
- Utilities, phone, streaming services
- Groceries or insurance premiums
- Retirement contributions
The proposed mortgage payment — principal, interest, property taxes, insurance, and HOA — gets added to this list when your DTI is calculated. You’re building the baseline that the mortgage will be added on top of.
Number 4: Your Debt-to-Income Ratio
Your DTI ratio is calculated directly from numbers 2 and 3 — your gross monthly income divided by your total monthly debt payments. It’s the primary filter lenders use to decide whether to approve your application and at what loan amount.
There are two DTI ratios that matter: the front-end (housing costs only ÷ income) and the back-end (all debts including housing ÷ income). Lenders look at both, but the back-end DTI is the one that most often limits borrowers.
| Loan Type | Max Front-End DTI | Max Back-End DTI |
|---|---|---|
| Conventional | 28% | 43–45% |
| FHA | 31% | 43–50% |
| VA | No limit | 41% preferred |
| USDA | 29% | 41% |
Your DTI changes every time you add or eliminate a debt — and every time you adjust the mortgage amount you’re applying for. Use the DTI ratio calculator to see exactly where you stand and model the impact of paying off specific debts before applying.
Number 5: Your Down Payment Amount
Your down payment is the cash you put toward the purchase price upfront. It directly determines your loan amount, whether you’ll pay PMI, what interest rate you qualify for, and which loan programs are available to you. More down payment means more options across every dimension.
| Down Payment | Loan Type Available | PMI? | Notes |
|---|---|---|---|
| 0% | VA or USDA only | No (VA/USDA) | Eligibility required |
| 3–3.5% | Conventional (3%) or FHA (3.5%) | Yes | Minimum entry point for most buyers |
| 5–10% | Conventional or FHA | Yes — until 20% equity | PMI cancellable on conventional |
| 20%+ | All conventional programs | No PMI ✅ | Best rates, lowest monthly cost |
Beyond the down payment itself, know where the money is coming from. Lenders require down payment funds to be “seasoned” — typically sitting in your account for at least 60 days. Large recent deposits trigger questions. If part of your down payment is a gift from family, there are specific gift letter requirements that vary by loan program.
Number 6: Your Cash Reserves After Closing
This is the most overlooked number in the entire first-time homebuyer process. Most buyers focus exclusively on saving for the down payment and closing costs — and then arrive at closing with their accounts nearly empty. Lenders look at this too, and more importantly, life does.
Cash reserves are the funds you have left over after paying your down payment and all closing costs. Lenders often require evidence of 2–6 months of mortgage payments in liquid assets. But beyond the lender requirement, the practical reality of homeownership makes this number critical:
- Moving costs: $1,500–$5,000
- Immediate repairs and purchases: $2,000–$10,000 in year one
- Ongoing maintenance reserve: $3,000–$6,000/year (1% of home value)
- Emergency fund: 3–6 months of total living expenses
A buyer who drains their savings to hit 20% down and arrives at closing with $2,000 left is in a more precarious position than a buyer who puts 10% down and keeps $20,000 in reserve. The first HVAC failure, roof leak, or plumbing emergency could send them straight to high-interest debt. Many financial planners suggest that if hitting 20% down requires leaving less than 3 months of expenses in reserve, 10% down with PMI is the financially safer choice.
Number 7: Your Maximum Affordable Home Price
This is the number that all the previous six feed into. It’s not what a lender will approve at maximum — it’s what you can comfortably afford given your income, debts, down payment, and the ongoing costs of homeownership in your target market.
Lenders will often approve you for more than you should spend. The pre-approval letter shows a ceiling, not a recommendation. Your real affordable price needs to account for:
- Mortgage principal and interest
- Property taxes — which vary enormously by location and add $300–$700/month in many markets
- Homeowner’s insurance
- PMI if applicable
- HOA fees if applicable
- Maintenance reserve (1% of home value annually)
- Utilities, which increase when you own more space
When all those costs are totalled, many buyers find their real comfortable price is $30,000–$80,000 below what the lender approved them for. That gap is the financial breathing room that makes homeownership enjoyable rather than stressful.
What to Do Once You Have All 7 Numbers
Once you’ve gathered all seven numbers, you have a clear picture of where you stand. Most first-time buyers fall into one of three categories:
Ready to apply now
Credit score above 680, back-end DTI below 43%, down payment saved and seasoned, 3+ months reserves after closing, stable documented income. You can start talking to lenders immediately. Get pre-approved at two or three lenders to compare rates and loan program options — not just the first lender you find.
6–12 months away
One or two numbers need work — typically credit score below 680, DTI above 43%, or down payment not yet saved. This is actually the most valuable position to be in, because you have time to make targeted improvements. Paying off a specific debt, reducing credit card balances, or adding a few months of savings can meaningfully change your outcome. Use the DTI calculator to model exactly how much each change improves your position.
12+ months away
Multiple numbers need significant improvement — credit below 620, DTI above 50%, minimal savings. This isn’t a failure; it’s useful information. A year of deliberate preparation — paying down specific debts, building credit, and saving consistently — can move you from this category to “ready” faster than most people expect. The key is knowing which numbers to work on first.
Opening new credit accounts (lowers average account age and adds hard inquiries), financing a car or furniture purchase (raises monthly debt payments and DTI), quitting or changing jobs to a different field (may restart income documentation requirements), making large cash deposits without documentation (triggers lender scrutiny), and co-signing any loan for someone else (adds to your debt obligations). These mistakes have derailed closings at the last minute for buyers who didn’t realise the impact.
Check Numbers 4 and 7 Right Now
Enter your income, monthly debts, down payment, and local tax rate — the mortgage affordability calculator shows your DTI ratio, maximum home price, monthly payment breakdown, and loan program eligibility instantly.
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