Debt-to-Income (DTI) Ratio Calculator
From gross monthly income and monthly debt payments, compute DTI and the allowable debt ceiling and borrowing headroom.
Input Data
Results
At a glance:DTI = monthly debt payments / gross monthly income x 100%. ≤36% ideal; 43% common mortgage ceiling; above is hard to approve. This tool also computes debt limit = income x allowed DTI% and headroom = limit - current debt. Example: 50k income, 15k debt → 30%; at 36% limit, ceiling 18k, headroom 3k. WARNING: HK uses DSR + stress test for mortgages (different thresholds). Education, not advice.
Formula
DTI = monthly debt payments / gross monthly income x 100%.
Monthly debt limit = gross income x allowed DTI%.
Additional headroom = max(0, debt limit - current monthly debt).
$$\text{DTI} = \dfrac{\text{MonthlyDebt}}{\text{GrossMonthlyIncome}} \times 100\%$$$$\text{MonthlyDebtLimit} = \text{GrossMonthlyIncome} \times \text{AllowedDTI}\%$$$$\text{AdditionalDebt} = \max(0,\ \text{MonthlyDebtLimit} - \text{MonthlyDebt})$$How to Use
- Enter your pre-tax monthly income.
- Enter total monthly debt payments.
- Set an allowed DTI% to see current DTI and borrowing headroom.
FAQ
What DTI is healthy?
Generally ≤36% is ideal and ~43% is the common mortgage ceiling; above 43% is hard to approve or carries higher rates. Lower DTI = less repayment pressure and better loan terms.
What counts as monthly debt?
Mortgage/rent, personal and car loans, credit-card minimums and fixed instalments. Everyday living expenses (food, utilities, transport) are NOT included. When unsure, include conservatively.
What should I enter for allowed DTI?
Your own or the lender's ceiling. Use 36% for a conservative health check, or 43% for the common mortgage ceiling. The tool derives your debt limit and headroom accordingly.
How does DTI differ from HK mortgage DSR?
HKMA requires banks to use DSR plus a stress test for residential mortgages: self-use DSR cap ~50% (40% if other mortgages/guarantees), with an interest-rate stress test. DSR is similar in spirit to DTI but differs in coverage, income definition and stress assumptions. This tool is for self-assessment; actual borrowing is per the bank under HKMA rules.
What is the formula and data basis?
Standard: DTI = monthly debt / gross monthly income x 100%; debt limit = gross income x allowed DTI%; headroom = limit - current debt (floored at 0). Health thresholds (36%/43%) are common international rules of thumb; HK mortgage DSR caps (50%/40%) follow HKMA. For reference only.
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References
Content review: Calculatorism Finance Team. Results are for reference only; please refer to the relevant authorities for the official figures.