Debt-to-Income Ratio Calculator
Both ratios a lender calculates, which of the two limits actually binds on your numbers, and what would have to change to pass.
The address carries whatever you changed, so anyone opening it sees these numbers. Nothing is saved on our side.
Debt-to-income ratio
37.8%
Total debt is above the limit. Clearing $160 of monthly payments would bring you inside it — or the housing payment has to come down to $2,240.
- 26.7%
- Limit 28% — passes
- 37.8%
- Limit 36% — over
- $3,400
- $1,000
- $2,240
- back-end limit binds
- Over
Where your income goes
Against the back-end limit. What is left after every debt payment is what the lender assumes you live on.
- Housing27%$2,400
- Other debt11%$1,000
- Everything else62%$5,600
- Gross monthly income$9,000
Which limit is stopping you
The two limits share one income, so the lower ceiling is the only one that matters.
- Front-end: 28% of income
- $2,520
- Back-end: 36% less $1,000 of other debt
- $2,240
- This is the one that binds.
Every dollar of non-housing debt removes a dollar of housing allowance. A $550 car payment is not just a car payment — it is $550 a month of house you cannot borrow.
How this calculator works
Two divisions, and the reason there are two.
front-end = housing ÷ gross income
back-end = all debt payments ÷ gross income
The first asks whether you can carry the house. The second asks whether you can carry the house alongside everything else you already owe.
Both use income before tax. That is not what you can spend, and it is what every lender uses — so a ratio worked out on take-home pay will not match the one they quote you.
What is assumed
- The limits you enter are the ones your lender applies. 28 and 36 are conventional guidelines, not rules.
- Housing includes tax, insurance and HOA — lenders count the whole payment, not just principal and interest.
- Deferred student loans are counted at whatever payment you enter. Many lenders impute one rather than using zero.
A worked example
$9,000 a month gross, a $2,400 housing payment, and $1,000 of other debt — a $550 car, $300 of student loans, $150 of card minimums.
| Front-end | 2,400 ÷ 9,000 |
|---|---|
| Total monthly debt | 2,400 + 1,000 |
| Back-end | 3,400 ÷ 9,000 |
| Housing the 28% limit allows | 9,000 × 0.28 |
| Housing the 36% limit allows | 9,000 × 0.36 − 1,000 |
| Most housing allowed | The back-end limit binds |
The housing payment passes on its own and the borrower still does not qualify, because the other $1,000 pushes the back-end ratio to 37.78%. Clearing $160 a month of it would bring them inside the limit — that is the whole gap.
Note what the car costs. Its $550 payment removes exactly $550 of housing allowance, so it is not a car payment competing with a mortgage payment — it is $550 a month of house that cannot be borrowed. That is the trade worth seeing before signing either.
Questions people ask
Because that is the convention every lender underwrites on. It is not what you can actually spend, and a ratio computed on your net pay will look much worse than the one the lender quotes back at you. Use gross so the numbers match theirs.
Payments that appear on a credit report and recur: mortgage or rent, car loans, student loans, credit-card minimums, personal loans, child support and alimony. Not utilities, groceries, phone bills, insurance premiums or subscriptions — anything you could stop paying next month is not debt for this purpose.
No. 43% is the threshold in the Qualified Mortgage rule and it is widely cited, but it is neither a legal maximum nor universal. Several programmes go higher with compensating factors — strong reserves, a large deposit, a high credit score. The limits are fields here rather than constants because they differ by programme and lender, and they change.
Usually yes, and often at an assumed payment rather than zero. Lenders commonly use a percentage of the balance where no payment is currently due. If a large deferred balance is the thing pushing you over, ask your lender specifically how they treat it before assuming it is excluded.
Clear the smallest monthly payment that removes a whole debt, not the largest balance. DTI is calculated on payments, not on what you owe — so paying a $12,000 car loan down to $2,000 changes nothing while the payment continues, and clearing it entirely removes the whole payment from the ratio.
Related calculators
An estimate using the limits you enter. Lenders apply their own thresholds, treat some debts differently, and consider factors beyond DTI.