MintNumber

№ 044 · Debt & loans cluster

Debt-to-Income Calculator

One number decides most lending: the share of your income already promised to debt. Enter your gross monthly income, your housing payment, and your other debts to get both ratios lenders check — and see exactly where you land against the 28/36 rule and the 43% mortgage cap.

Front-end & back-end · the 28/36 rule

Turning the ratio into a price? The Affordability Calculator runs the same 28/36 rule backward to a max home price, and the Credit Card Payoff Calculator shows how fast paying debt down lifts your ratio.

Your income01
$
Housing02
$
Other monthly debts03
$
$
$
$
Back-end DTI · the ratio lenders gate on

38.33%

$2,300.00/mo of debt on $6,000.00/mo income · front-end 23.33%

Manageable — within the 43% qualified-mortgage cap
Where your debt sits against income
36%43%
Housing Other debt Free income
Front-end (housing)23.33%
Back-end (total)38.33%
Total monthly debt$2,300.00
Over the 36% line$140.00/mo

Lenders weigh two ratios: the front-end (housing alone, target ≤ 28%) and the back-end (all debt, target ≤ 36%, with most conventional loans capped near 43–45%). Yours is 38.33% back-end. You're about $140.00/mo over the 36% guideline — paying down $140.00 of monthly obligations would bring you to it. DTI uses gross (pre-tax) income and the minimum required payments, not your actual spending.

How it works · methodology

The math, in the open.

front-end DTI = housing payment ÷ gross monthly income × 100
back-end DTI  = total monthly debt ÷ gross monthly income × 100

total monthly debt = housing + auto + student + cards + other

guidelines: front-end ≤ 28%, back-end ≤ 36% (43% QM cap)
Two ratios from the same income: housing alone (front-end) and every debt (back-end). The back-end ratio is the one lenders gate on; the 28/36 rule and the 43% qualified-mortgage cap are the reference lines.
gross income
Monthly income before taxes
housing
Rent, or mortgage principal + interest + tax + insurance
other debt
Auto, student, credit-card minimums, personal loans, support
DTI
Debt payments as a % of gross income

Assumptions & limits

  • Uses gross (pre-tax) income, the figure lenders underwrite to — your take-home is lower.
  • Counts minimum required monthly payments, not actual spending or revolving balances in full.
  • The 28/36 rule and 43% QM cap are common guidelines; individual lenders and loan programs vary (FHA, VA, and others allow higher).
  • Utilities, insurance outside escrow, and day-to-day costs are not debts and are excluded. A general estimate, not a lending decision.

Sources

By the MintNumber Editorial Team·Reviewed
Frequently asked

Questions about DTI

What is a debt-to-income (DTI) ratio?
Your DTI is the share of your gross (pre-tax) monthly income that goes toward debt payments. Lenders use it as a quick read on whether you can take on another payment: the lower the ratio, the more breathing room. There are two versions — the front-end ratio counts only housing, and the back-end ratio counts every monthly debt. When a lender talks about “your DTI,” they almost always mean the back-end number.
What is the difference between front-end and back-end DTI?
Front-end DTI is your housing payment divided by gross monthly income — rent, or a mortgage’s principal, interest, taxes, and insurance. Back-end DTI adds everything else: car loans, student loans, credit-card minimums, personal loans, and court-ordered payments like child support. Back-end is the ratio that gates a mortgage approval, because it captures your whole obligation, not just the roof over your head.
What is a good debt-to-income ratio?
The classic 28/36 rule says keep housing at or below 28% of gross income (front-end) and total debt at or below 36% (back-end). Many conventional loans stretch to 43–45% back-end, and the federal qualified-mortgage rule treats 43% as a key threshold. Below 36% is comfortable, 36–43% is workable but watched, above 43% is stretched, and above 50% will see most lenders decline. Lower is always better — it means more of your income is yours.
How do I lower my DTI?
Two levers: shrink the debt or grow the income. Pay down or pay off the balances with the highest minimum payments (a car loan or credit card often moves the needle fastest), avoid taking on new monthly obligations before a mortgage application, and don’t close old credit lines right before applying. On the income side, a raise, a side income, or adding a co-borrower’s income all push the ratio down. Even paying off one small loan can drop you below a lender’s threshold.
Does DTI use gross or net income?
Gross — your income before taxes and deductions. That’s deliberate on the lender’s part and a little optimistic from yours: your take-home pay is lower, so the slice of your actual cash that goes to debt is bigger than the ratio suggests. It also counts the minimum required payments, not what you really spend. Treat the DTI as the lender’s lens, and budget against your net pay separately.
How does DTI relate to how much house I can afford?
They’re the same rule from two directions. DTI takes your income and debts and tells you the ratio; the affordability calculator takes that same 28/36 rule and works backward to the largest home price and payment it allows. If your back-end DTI is already high, your affordable price shrinks, because less of your income is free for a new housing payment.