Debt-to-Income Calculator

What this calculator is, and when to reach for it

Your debt-to-income ratio is the single number lenders reach for first, and one most people have never worked out. It is simply the share of your gross monthly income already committed to debt payments. If you earn 7,500 a month before tax and 2,620 of it goes out to a mortgage, a car, a student loan, and card minimums, your ratio is 34.9%. That is it. No credit history, no score, no judgement about the kind of debt. Just how much of your income is already spoken for.

It carries so much weight because it measures something a credit score cannot: capacity. A score describes how reliably you have repaid in the past. A ratio describes whether you have room to take on more now. Someone with a flawless record can still be declined for having no headroom, and understanding that distinction explains a great many otherwise baffling lending decisions.

There are two versions, and they are worth keeping straight. The front-end ratio counts only housing. The back-end ratio counts every monthly debt payment including housing, and it is the one people usually mean by "DTI". This calculator works out both, because a lender assesses both, and because the gap between them tells you how much of your obligation is housing and how much is everything else.

Reach for this page before you apply for anything significant, when you are deciding which debt to attack first, or when a lending decision has not gone the way you expected and you want to see the picture the lender saw.

What counts, and what does not

Include the recurring obligations that appear on a credit file: mortgage or rent where the lender counts it, car finance, student loans, personal loans, card minimum payments, and any court-ordered payments such as maintenance or child support. Use the minimum due on cards, not what you usually pay, because that is what a lender uses.

Leave out ordinary living costs. Groceries, utilities, phone bills, insurance premiums, subscriptions, and childcare are not debt payments, and none of them belong in this ratio. This surprises people, and it cuts both ways: your ratio can look comfortable while your budget is anything but, which is exactly why a ratio should never be mistaken for an affordability test.

On the income side, use gross income, before tax and deductions. If your earnings vary, lenders typically look at an average over a period rather than your best month, so an honest average will match their view more closely than an optimistic one.

Where to go next

If your ratio is the obstacle, the fastest fix is usually removing a payment rather than earning more. The credit card payoff calculator shows what clearing a balance takes, and the debt consolidation calculator shows whether combining balances into one payment would help or simply stretch the debt out.

If you are heading toward a property purchase, carry the ratio into the affordability calculator, which applies exactly these limits to work out a loan, and the qualification calculator, which frames the same ground the way a lender would. The mortgage calculator tells you what a prospective payment would add to your ratio before you commit to it.

For the wider plan, the debt payoff journey lines up the payoff, consolidation, and transfer options side by side, and the balance transfer calculator covers promotional offers.

How the ratio is worked out

The arithmetic is deliberately simple. The judgement is in what you feed it.

back-end DTI = (total monthly debt ÷ gross monthly income) × 100   |   front-end DTI = (housing ÷ gross monthly income) × 100

total monthly debt

every recurring debt payment, housing included

housing

the housing payment alone, including escrow where collected

gross monthly income

income before tax and deductions, averaged if it varies

Why lenders use gross rather than take-home

Take-home pay differs enormously between two people earning the same amount, depending on where they live, their tax position, pension contributions, and benefits. Gross income is comparable across everybody, so lending limits can be written once and applied consistently.

The cost of that consistency is that the ratio flatters you. A 36% ratio against gross income can be closer to half of what actually reaches your account. Keep that in mind when reading your own number.

The thresholds, and what they mean in practice

The conventional guideline pairs a front-end ratio of about 28% with a back-end ratio of about 36%. Below those, most lenders see comfortable headroom. Many mainstream programmes will go higher, frequently into the low forties, and government-backed or specialist products can allow more still, particularly with compensating factors such as a large deposit or substantial savings.

Past roughly the mid-forties, options narrow sharply and pricing worsens. But these are conventions rather than rules, and they differ by country, product, and lender. Treat any single threshold you read as a signpost rather than a boundary.

Why clearing a small debt can beat a pay rise

The ratio is a fraction, and you can improve it from either end. Raising income lifts the denominator, but income arrives after tax and usually in modest increments. Removing a payment cuts the numerator directly and immediately.

A 450 car payment removed from a 7,500 income lowers the ratio by six full percentage points. Matching that by earning more would take roughly 1,250 a month of additional gross income. This is why "pay off the car before applying" is such durable advice: the smallest balance with the largest monthly payment is almost always the most efficient thing to remove, regardless of its interest rate.

The trap in stretching a loan

Because the ratio counts payments rather than balances, refinancing a debt over a longer term lowers your ratio without reducing what you owe by a single unit. That can genuinely help you qualify, and it is a legitimate tool. It also means you will pay more interest overall.

The ratio simply cannot see this distinction, which is its most important blind spot. A borrower who has stretched every obligation to its longest available term can show an excellent ratio while being in a materially worse position than someone with a higher one.

What this page assumes

The calculator converts your income before taxes into a monthly figure, then divides your monthly debt payments by it to get the debt share of income.

Yearly income before taxes is divided by 12. Monthly income is used as entered. The result is shown as a percentage.

Worked examples, step by step

Take a household earning 7,500 a month before tax, with a 1,800 housing payment, 450 on car finance, 220 on a student loan, and 150 in card minimums.

Adding it up

The front-end ratio is 24.0%, comfortably inside the conventional 28%. The back-end ratio is 34.9%, just under the 36% guideline with only 80 a month of room to spare. This household would likely be accepted by a mainstream lender, but the margin is thin enough that a single new commitment would change the answer.

That 80 is worth sitting with. A modest new car payment, a phone contract reported as credit, or a small loan would push the ratio past the conventional threshold and could move this file from straightforward to borderline.

What clearing the car does

Remove the 450 car payment and the total falls to 2,170, taking the back-end ratio from 34.9% to 28.9%. Six percentage points, from one decision, with no change in income.

To achieve the same improvement by earning more, this household would need roughly 1,250 a month of extra gross income, or about 15,000 a year. That comparison is why lenders so often suggest clearing a balance before applying, and why the smallest debt with the biggest payment deserves attention first when qualifying is the goal.

Where the ratio misleads

Now imagine the same household refinances the car over a much longer term, halving the payment to 225. The ratio improves to 31.9% and the file looks stronger. Nothing has been repaid, and the total interest has gone up.

Equally, a household with a 30% ratio and heavy childcare costs may be under far more real pressure than one at 38% with none, because childcare never appears in the calculation. The ratio is a lending screen, not a picture of your finances.

The vocabulary, on and around this page

Debt-to-income ratio

The share of gross monthly income committed to recurring debt payments, expressed as a percentage. Lenders use it to judge capacity for further borrowing.

Front-end ratio

The housing payment alone as a share of gross monthly income. A commonly cited guideline is around 28%.

Back-end ratio

All recurring debt payments including housing as a share of gross monthly income. This is what people usually mean by DTI, and the conventional guideline is around 36%.

Gross monthly income

Income before tax and deductions. Lenders use it because it is comparable between borrowers, though it flatters the ratio relative to take-home pay.

Minimum payment

The smallest amount a card issuer requires each month. Lenders count this figure in the ratio, not the larger amount you might normally pay.

Recurring debt

Regular obligations such as loans, finance agreements, and card minimums. Living costs like utilities and groceries are excluded.

Headroom

The distance between your current ratio and a lender’s limit, expressed as the monthly payment you could still add before crossing it.

Capacity

Your ability to take on further debt given existing commitments. It is what the ratio measures, distinct from your willingness to repay.

Credit utilisation

The share of your available credit currently in use. It affects credit scores but is a separate measure from debt-to-income.

Compensating factors

Strengths such as a large deposit, significant savings, or a long stable earning record that can persuade a lender to accept a higher ratio.

Residual income

What remains after debts and living costs are paid. Some lending programmes test it because it captures household circumstances the ratio ignores.

Qualifying payment

The payment a lender uses in the ratio, which may be higher than your actual one if rules require a stressed rate or an assumed minimum.

Deferred debt

An obligation currently paused, such as a student loan in deferment. Many lenders still count an assumed payment for it.

Term extension

Refinancing a debt over a longer period to lower its payment. It improves the ratio without reducing the balance, and usually increases total interest.

Stress test

Reassessing affordability at a higher rate than the one offered, to check the borrower could still cope if rates rose.

Underwriting

The lender’s full assessment of credit, income, employment, and security. The ratio is one input among several.

Credit score

A measure of how reliably you have repaid in the past. It is independent of the ratio, which is why a strong score does not guarantee approval.

Co-borrower

A second person on the application whose income and debts are both included, which can raise or lower the combined ratio.

Court-ordered payment

An obligation such as maintenance or child support. Lenders generally include these as recurring debt.

Payment shock

A large increase between current housing costs and proposed ones. Lenders watch it alongside the ratio because it predicts strain.

Common mistakes, and what this page will not do

• Using take-home pay instead of gross income. The ratio is defined against income before tax. Net pay produces a much higher figure than any lender would calculate.
• Entering what you usually pay on cards. Lenders count the required minimum, not your generous overpayment. Using the larger figure overstates your ratio.
• Including living costs. Groceries, utilities, phones, insurance, and childcare are not debt payments and do not belong here, however much they dominate a real budget.
• Forgetting a paused or deferred obligation. A student loan in deferment usually still counts, often at an assumed payment. Leaving it out produces a ratio no lender will recognise.
• Omitting the payment you are applying for. When testing whether you qualify, include the prospective housing payment. The ratio a lender cares about is the one after the new debt exists.
• Treating 36% as a hard cut-off. It is a convention. Many programmes go well beyond it, and limits vary by country, product, and lender.
• Mistaking a good ratio for affordability. The calculation cannot see childcare, commuting, or medical costs. A comfortable ratio and a comfortable budget are not the same thing.
• Stretching loan terms purely to pass. A longer term lowers the payment and flatters the ratio while leaving the balance untouched and increasing total interest.
• Assuming a strong credit score compensates. Score and ratio measure different things. A spotless record does not create capacity that the income does not support.

What this calculator leaves out: This calculator does not check your credit file, verify income, apply any specific lender’s rules or overlays, count living costs, assume payments for deferred obligations, or reflect country-specific lending regulations. It divides the payments you enter by the income you enter. Lenders may calculate some payments differently, and a decision comes only from a lender.

Frequently asked questions