Debt-to-Income Ratio Calculator
What's your DTI โ and will a lender approve your loan? Calculate front-end and back-end DTI, check mortgage qualification thresholds, and get a concrete plan to improve your ratio.
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How to Use This Calculator
Tab "My DTI"
Enter your gross monthly income (before taxes) and each category of monthly debt payment: housing (mortgage or rent), car loans, student loans, credit card minimums, and any other obligations. The calculator instantly shows your front-end DTI (housing only) and back-end DTI (all debts), with a colour-coded rating and gauge bar.
Tab "Mortgage Qualification"
Enter your income, your existing monthly debts (excluding any current housing), and the proposed new mortgage payment. The calculator shows your DTI with the new mortgage and checks it against three common lending thresholds: conventional (28% front / 36% back), FHA-style programs (43%), and some lenders (up to 50%).
Tab "Improve My DTI"
Enter your current income, total monthly debts, and a target DTI (e.g. 36%). The calculator gives you two actionable options: exactly how much monthly debt to eliminate, or how much gross income to add, to reach your goal.
The Formulas
Front-end DTI = Housing payment ÷ Gross monthly income × 100
Back-end DTI (total debt ratio):
Back-end DTI = All monthly debt payments ÷ Gross monthly income × 100
Target debt to eliminate:
Debt to cut = Current debts − (Target DTI% ÷ 100 × Income)
Income to add:
Income needed = Current debts ÷ (Target DTI% ÷ 100) − Current income
Note: Always use gross income (before taxes), not take-home pay.
All calculations use standard lender guidelines. No country-specific tax rates or local regulations are applied. Results are indicative estimates only.
DTI Thresholds at a Glance
| Back-end DTI | Rating | Lender view |
|---|---|---|
| Under 28% | Excellent | Lowest risk; best rates available |
| 28% โ 36% | Good | Standard conventional mortgage approval range |
| 36% โ 43% | Fair | Possible with strong credit; some programs |
| 43% โ 50% | Difficult | Limited programs; usually needs compensating factors |
| Over 50% | Very Unlikely | Most lenders will decline; work on reduction first |
Front-end DTI (housing only) thresholds: under 28% conventional; under 31% FHA-style. These are guidelines โ individual lenders set their own policies.
Worked Examples
Example 1 โ Typical Renter: $6,000/mo income
Monthly debts: rent $1,500, car $350, student loan $280, credit card minimums $120. No other debts.
Front-end: $1,500 / $6,000 = 25.0% (under the 28% conventional threshold). Back-end: $2,250 / $6,000 = 37.5% (between 36โ43%; fair โ acceptable to some lenders, tight for conventional mortgages).
Example 2 โ Mortgage Qualification: Same borrower, proposed $1,800 mortgage
The renter above wants to buy. Their rent (previously $1,500) would be replaced by a $1,800 mortgage payment. Existing non-housing debts: $750/month.
At 42.5% back-end, this borrower is borderline โ likely declined for conventional loans, but may qualify for FHA or similar programs. Paying off the car ($350/month) would bring back-end DTI to 36.7%, within conventional range.
Example 3 โ Improve My DTI: From 37.5% to 36%
The renter from Example 1 wants to reach the standard 36% back-end threshold before applying for a mortgage.
To reach 36%: eliminate $90/month of debt (e.g. pay off a small balance) OR earn an extra $250/month gross. Option A is usually faster โ a single extra payment on a credit card could achieve this immediately.
Understanding DTI: Key Concepts
Front-End vs Back-End DTI
Most lenders look at two DTI numbers. The front-end ratio (housing ratio) includes only your housing payment divided by income โ it shows how much of your income goes to shelter. The back-end ratio (total debt ratio) includes all monthly debt obligations: housing, car, student loans, credit cards, personal loans, alimony, and child support. Lenders care most about back-end DTI as it reflects your total debt burden.
Gross Income, Not Net
Always use gross income (before taxes and deductions) when calculating DTI โ the same figure you report on a loan application. If your annual salary is $72,000, use $6,000/month even if you only take home $4,500 after tax. Including income from a spouse or co-borrower? Add it to the gross figure only if they are named on the loan.
What Counts as a Debt Payment
Include all monthly obligations that appear on your credit report or loan documents: mortgage or rent payments, car loans, student loans, minimum credit card payments, personal loans, medical debt payment plans, alimony, and child support. Do not include living expenses like groceries, utilities, subscriptions, or insurance premiums โ lenders do not count these.
Why DTI Matters for Mortgages
DTI is one of the three core factors in mortgage underwriting alongside credit score and loan-to-value ratio. A lower DTI signals to lenders that you have enough cash flow to comfortably service new debt. Conventional guidelines (28/36) have been the industry standard for decades. Government-backed programs (FHA, VA, USDA) often allow higher back-end DTI โ up to 43โ50% โ to help more borrowers qualify, but at the cost of additional fees or insurance.
How to Improve Your DTI
You have two levers: reduce debt or increase income. On the debt side, focus on paying off accounts that will be eliminated entirely (removing the monthly payment completely) rather than partially paying down balances. On the income side, a raise, promotion, second job, freelance contract, or rental income all count โ as long as the income is documented and has a history of at least two years for most loan programs.