Getting approved for a loan and being able to comfortably afford one are two different things. Lenders will tell you the maximum amount they’ll lend — which is the maximum they believe you’ll repay, not the maximum that’s healthy for your finances. Here’s how to calculate an honest answer.
Quick Answer
The key metric is your debt-to-income ratio (DTI): total monthly debt payments divided by gross monthly income. Keep total debts below 36% of gross income for a comfortable margin; most lenders approve up to 43%. To find your affordable loan amount: calculate your available monthly payment (36% of gross income minus existing debt payments), then use the Loan Calculator to find the loan amount that payment supports at your expected rate and term. Borrow 15–20% below what you qualify for to keep a buffer.
The Debt-to-Income Ratio
DTI is the primary number lenders use to evaluate affordability — and it’s the right number for you to use too.
DTI = Total Monthly Debt Payments ÷ Gross Monthly Income × 100
“Total monthly debt payments” includes: the new loan payment, existing car loans, student loans, credit card minimum payments, and any other loan obligations. It does not include rent, utilities, groceries, or insurance — those are living expenses, not debt.
DTI benchmarks:
- Below 28%: Comfortable — significant financial flexibility
- 28–36%: Manageable — standard lender threshold for best terms
- 36–43%: Qualifying — approved by most lenders, but tight
- 43–50%: Risky — most conventional lenders will decline; limited cushion
- Above 50%: Overextended — high risk of default if income disrupted
Working Out Your Affordable Payment
Step 1: Calculate your gross monthly income Divide your annual pre-tax salary by 12. If you earn $72,000/year: $72,000 ÷ 12 = $6,000/month.
Step 2: Apply the 36% guideline $6,000 × 0.36 = $2,160 maximum total monthly debt payments for comfortable affordability.
Step 3: Subtract existing debt payments If you have $400/month in car payments and $250/month in student loans: $2,160 − $650 = $1,510 available for the new loan.
Step 4: Find the loan amount that payment supports At 10% APR for 48 months, $1,510/month supports approximately $59,000. At 7% APR for 36 months, it supports approximately $49,000. Use the Loan Calculator to model your specific rate and term.
Salary-Based Affordability Reference
The table below assumes no existing debt and a 36% DTI guideline. Real affordability is lower if you have existing debt payments.
| Annual Salary | Monthly Income | 36% DTI Limit | Loan at 9%/36mo | Loan at 9%/60mo |
|---|---|---|---|---|
| $40,000 | $3,333 | $1,200 | $37,500 | $56,000 |
| $60,000 | $5,000 | $1,800 | $56,000 | $84,000 |
| $80,000 | $6,667 | $2,400 | $75,000 | $112,000 |
| $100,000 | $8,333 | $3,000 | $94,000 | $140,000 |
| $120,000 | $10,000 | $3,600 | $112,500 | $168,000 |
These are the upper limits at 36% DTI with no other debt. With existing payments, reduce accordingly.
What Lenders Consider vs What You Should Consider
Lenders care about: will you repay this loan? Their risk model allows DTIs up to 43–45% because most borrowers at that level do repay — but many are financially stressed while doing so.
You should also care about: what happens to my finances if I lose my job for 2 months? Can I still save for retirement? Can I handle an unexpected $3,000 expense?
At 36% DTI, a $1,000 income disruption is manageable. At 43% DTI, the same disruption could mean late payments, fees, and credit damage. The lender’s maximum is a ceiling, not a recommendation.
A practical rule: If borrowing the maximum means you can’t maintain a $1,000/month savings rate, the loan is too large. Loans that crowd out all discretionary savings create fragility.
Total Cost, Not Monthly Payment
Monthly payment is the most visible number — and the most misleading. A lower payment achieved by extending the term often means significantly higher total cost.
| Loan | Rate | Term | Monthly Payment | Total Interest | Total Cost |
|---|---|---|---|---|---|
| $30,000 | 9% | 36 months | $954 | $3,344 | $33,344 |
| $30,000 | 9% | 60 months | $622 | $7,320 | $37,320 |
| $30,000 | 9% | 84 months | $478 | $10,152 | $40,152 |
The 84-month loan has half the monthly payment of the 36-month loan — but costs $6,808 more in total interest. When evaluating affordability, look at total cost, not just whether the monthly payment fits your budget.
A Conservative Approach
- Calculate your true 36% DTI limit including all existing obligations.
- Subtract a 15% buffer from that limit — this is your target maximum payment.
- Choose the shortest term your budget allows, not the longest.
- Add 10% to your estimated monthly payment and verify it still works. Rates sometimes come in higher than expected; total cost often includes fees.
Use the Loan Calculator to model the exact payment for any loan amount, rate, and term combination — and to see how different terms change total interest paid.