Debt-to-income ratio (DTI) calculator
Debt-to-income (DTI) is the share of your gross monthly income already committed to fixed debt payments. Lenders use it to approve or decline mortgages, personal loans, and cards. This tool totals your payments, computes DTI %, assigns a rating, and shows how much room you still have under a 36% guideline.
With the calculator defaults: 15,000 income, housing 3,000, car 1,500, and cards 500: monthly debt is 5,000, DTI is 33.33% (good), the 36% max recommended debt is 5,400, and available capacity is 400.
What this tool calculates
- Total monthly debt (housing/rent + car + card minimums + student loans + other)
- DTI % = debts ÷ gross income × 100
- Rating: excellent, good, acceptable, high, or critical
- Max recommended debt at 36% of income
- Available capacity = 36% max − current debt (floored at 0)
DTI formula
DTI (%) = (total monthly debts ÷ gross monthly income) × 100
Max recommended (36%) = income × 0.36 Available capacity = max(0, max recommended − debts)
Income is gross (before taxes). Some lenders also look at net pay or a housing-only “front-end” ratio; this page models a simple educational back-end DTI with all fixed debts.
Step-by-step example (defaults)
Inputs: income 15,000 · housing/rent 3,000 · car 1,500 · cards 500 · student 0 · other 0
- Total debt = 3,000 + 1,500 + 500 = 5,000
- DTI = 5,000 ÷ 15,000 × 100 = 33.33%
- Rating: good (≤ 36%)
- 36% max = 15,000 × 0.36 = 5,400
- Available capacity = 5,400 − 5,000 = 400
Add a student loan of 800 and other debts of 200, and debt becomes 6,000, DTI 40% (acceptable), and 36% capacity 0.
Reference table (same engine as the calculator)
Rounded with the on-page logic. Use the form above for your exact case.
| Income / mo | Housing/rent | Car | Cards | Student | Other | Total debt | DTI | Rating | 36% max | Capacity |
|---|---|---|---|---|---|---|---|---|---|---|
| 15,000 | 3,000 | 1,500 | 500 | 0 | 0 | 5,000 | 33.33% | Good | 5,400 | 400 |
| 15,000 | 3,000 | 1,500 | 500 | 800 | 200 | 6,000 | 40% | Acceptable | 5,400 | 0 |
| 8,000 | 2,500 | 0 | 400 | 0 | 300 | 3,200 | 40% | Acceptable | 2,880 | 0 |
| 25,000 | 4,500 | 2,000 | 1,000 | 0 | 0 | 7,500 | 30% | Good | 9,000 | 1,500 |
| 12,000 | 0 | 1,800 | 1,500 | 0 | 500 | 3,800 | 31.67% | Good | 4,320 | 520 |
| 20,000 | 5,000 | 2,500 | 2,000 | 0 | 500 | 10,000 | 50% | High | 7,200 | 0 |
| 18,000 | 2,000 | 0 | 300 | 0 | 0 | 2,300 | 12.78% | Excellent | 6,480 | 4,180 |
Rating bands (engine thresholds)
| DTI | Rating | Practical read |
|---|---|---|
| ≤ 20% | Excellent | Plenty of room for new credit |
| 21–36% | Good | Healthy zone; many loans and better terms |
| 37–43% | Acceptable | Common edge for conventional mortgages |
| 44–50% | High | New credit harder or more expensive |
| > 50% | Critical | Over-indebtedness risk |
Lender cutoffs vary (often ~36–43% back-end). Treat 36% here as a widely used “good” guideline, not a universal legal rule.
Which debts to include
Include (fixed or minimum monthly payment):
- Mortgage or rent (many underwriters treat housing as an obligation)
- Auto loan payment
- Credit-card minimums (not full balances)
- Personal or student loan payments
- Other fixed installment debts
Usually not in classic underwriting DTI:
- Groceries, variable transport, utilities (budget items)
- Voluntary savings and investments
- Full card balances (use the minimum or fixed payoff amount)
How to lower DTI before applying
- Pay principal faster on expensive cards and loans. Model with credit card payment and debt payoff.
- Avoid new debt for 3–6 months before a mortgage or large loan.
- Increase documentable income (stable salary or fees); DTI uses gross pay.
- Refinance or consolidate only if the new payment is lower and the term is sane. Compare with personal loan.
- Cross-check housing payment with mortgage and your monthly budget.
Common mistakes
- Mixing net and gross income vs what the lender requests
- Leaving out rent before you have a mortgage
- Entering full card balance instead of the minimum/payment
- Ignoring joint debts or loans at other lenders
- Passing DTI while cash flow is still negative
What’s included and what’s not
Included (reference model):
- Five monthly debt inputs
- DTI to two decimals
- Rating scale matching the calculator code
- Educational 36% cap and residual capacity
May differ at your lender:
- Internal cutoffs (30%, 35%, 40%, housing-only front-end)
- Whether rent, insurance, or payroll deductions count
- Credit history, job stability, and loan-to-value rules
- Down payment, collateral, or co-borrower requirements
This calculator is educational. It does not guarantee loan approval or replace a bank, credit union, or licensed advisor. Thresholds and documentation change by product and institution: confirm current criteria before you sign.
FAQ
The percentage of gross monthly income already going to fixed debt payments: total monthly debts ÷ gross income × 100.
Here, ≤36% is “good” and ≤20% is “excellent.” Many mortgages tighten near 43%. Your lender may be stricter.
Yes if it’s your current or expected housing obligation. Many underwriters treat rent as housing payment capacity.
The minimum payment or fixed monthly amount you actually pay: not the full balance.
It’s a common international “healthy” back-end guide. If your lender allows 40–43%, you may have more room in practice; if tighter, less.
Cut payments: pay down high-rate debt, avoid new credit, refinance only when the payment drops. See debt payoff, credit card payment, and early loan payoff.