See your front-end and back-end DTI and how lenders will read it
In plain terms: it works out what share of your income already goes to debt — the number lenders check first when you apply for a mortgage or loan. Enter your gross monthly income, your housing payment, and your other monthly debt payments, and it returns your front-end DTI (housing only) and back-end DTI (all debt), a plain-English rating, and how you compare with the 28/36 rule and Fannie Mae limits. Switch the country to Canada to get your GDS and TDS ratios checked against CMHC limits instead. Everything runs in your browser — your income and debt figures are never uploaded or stored.
Debt-to-income calculator shows your front-end and back-end DTI — the two percentages lenders use to judge whether you can afford a new loan — from just three numbers: your gross monthly income, your housing payment, and your other monthly debt payments. Enter those, press Calculate DTI, and you will instantly see both ratios, a plain-English rating, your total monthly debt, and how your ratio compares with the 28/36 rule and Fannie Mae's published limits. In Canada, choose Canada as the country to see your Gross Debt Service (GDS) and Total Debt Service (TDS) ratios instead.
Everything runs entirely in your browser. Nothing you type is uploaded, stored, or shared, so you can model different scenarios — a bigger mortgage, a paid-off car loan, a raise — with complete privacy. That makes it easy to answer the questions that matter before you apply: is my DTI low enough to qualify, how much of a housing payment can I take on, and which debt should I clear first to move the needle?
DTI is a simple division. You add up your required monthly debt payments, divide by your gross (pre-tax) monthly income, and multiply by 100 to get a percentage. The key is to use gross income — what you earn before taxes and deductions — because that is the figure lenders underwrite against, not your take-home pay.
There are two versions of the ratio, and this calculator shows both:
For example, on a $6,000 gross monthly income with a $1,500 housing payment and $500 in other debts, front-end DTI is $1,500 ÷ $6,000 = 25%, and back-end DTI is $2,000 ÷ $6,000 = about 33%.
The table below uses the 28/36 rule and the limits Fannie Mae publishes for the conventional loans it buys. Other loan programs and lenders set their own limits, so check with your lender.
| Back-End DTI | How Lenders View It | What It Means for You |
|---|---|---|
| 36% or below | Healthy | Within the 28/36 rule and Fannie Mae's 36% limit for manually underwritten loans. |
| Over 36% to 45% | Manageable | Fannie Mae allows up to 45% on manually underwritten loans when credit score and reserve rules are met. |
| Over 45% to 50% | High | Fannie Mae allows up to 50% only for loans approved through its Desktop Underwriter system. |
| Over 50% | Very high | Above Fannie Mae's 50% maximum, so a conventional loan it buys is not possible until the ratio comes down. |
The most widely cited DTI guideline is the 28/36 rule. It suggests spending no more than 28% of gross monthly income on housing (front-end) and no more than 36% on total debt including housing (back-end). The rule has stuck around because it maps to a budget that can absorb the payment without strain, leaving room for savings, emergencies, and the everyday costs that never appear on a credit report.
Think of 28/36 as the comfortable zone rather than a hard wall. Plenty of borrowers qualify above it, but staying within the rule gives you the strongest application and the least financial stress once the loan is in place.
For years, a back-end DTI of 43% was the federal upper limit for a general qualified mortgage, a home loan that meets federal ability-to-repay standards. That is no longer the rule. The Consumer Financial Protection Bureau's General QM final rule replaced the 43% DTI limit with a price-based test: a first-lien loan qualifies only if its APR is less than 2.25 percentage points above the average prime offer rate for a comparable loan, with higher thresholds for smaller loans. The rule took effect on March 1, 2021, and lenders had to use it for applications received on or after October 1, 2022 (Federal Register).
Lenders must still consider your DTI or your residual income and check your income and debts, but the rule does not set a DTI number. Limits now come from loan programs. For example, Fannie Mae's Selling Guide allows a total DTI of up to 36% on manually underwritten loans, up to 45% when credit score and reserve rules are met, and up to 50% for loans approved through its Desktop Underwriter system. The higher your ratio, the more the rest of your application has to make up for it.
Canadian lenders use two ratios instead of front-end and back-end DTI. Gross Debt Service (GDS) is your mortgage payment (principal and interest), property taxes, heating and half of any condo fees, divided by your gross income. Total Debt Service (TDS) adds all your other debt payments, such as car loans, student loans and credit card payments. For insured mortgages, CMHC limits GDS to 39% and TDS to 44%, and the mortgage payment is worked out at the greater of your contract rate plus 2% or 5.25%. Choose Canada as the country above to calculate both ratios.
Getting an accurate DTI depends on including the right items. Lenders count the required monthly payments that appear on your credit report, and nothing else.
| Counts as debt (include) | Not counted (exclude) |
|---|---|
| Rent or mortgage (with taxes & insurance) | Utilities (electric, water, gas) |
| Car loans and leases | Cell phone and internet bills |
| Student loans | Groceries and gas |
| Minimum credit-card payments | Streaming and subscriptions |
| Personal and installment loans | Health, auto & life insurance premiums |
| Child support & alimony (court-ordered) | Taxes and everyday spending |
For the "Other Monthly Debt Payments" field, add up your car, student, and personal loan payments plus your credit-card minimums — not your full balances. Enter your housing payment separately so the calculator can split out the front-end ratio.
Each figure answers a specific question, and each points to an action:
The calculator also shows two pass/fail tiles for the 36% and 50% limits (39% GDS and 44% TDS in Canada mode), plus a short plain-language summary that translates your specific numbers into what they mean and how much monthly debt room you have left.
Suppose Alex earns $6,000 gross per month, pays $1,500 for housing, and has $700 in other monthly debt (a $400 car loan and $300 in card minimums and a student loan). Here is the math:
Now change one thing — Alex pays off the $400 car loan. Total debt drops to $1,800, and back-end DTI falls to $1,800 ÷ $6,000 = 30%, moving comfortably into healthy territory and freeing up room to qualify for a larger mortgage. That single payoff is the kind of move this calculator makes visible instantly.
This calculator uses the standard lender formula: front-end DTI = housing payment ÷ gross monthly income × 100, and back-end DTI = (housing + all other monthly debt) ÷ gross monthly income × 100. The US rating bands use the 28/36 rule and Fannie Mae's limits (36%, 45% and 50%). In Canada mode, GDS = (mortgage payment + property taxes + heating + 50% of condo fees) ÷ gross monthly income × 100 and TDS = (GDS costs + other monthly debt) ÷ gross monthly income × 100, checked against CMHC's 39% and 44% limits. Exact limits vary by lender, loan program, and compensating factors such as credit score, reserves, and down payment. All math runs in your browser and no income or debt data is stored or transmitted.
Formula and guidance last reviewed October 2026. DTI limits, the qualified-mortgage rule, and lender overlays change over time and vary by program — verify current requirements with your lender. This tool is for planning and education, not financial advice.
Planning the whole picture? These free, private calculators pair naturally with your DTI:
Your debt-to-income ratio, or DTI, is the share of your gross monthly income that goes toward paying debts. Add up your required monthly debt payments, divide by your gross (pre-tax) monthly income, and multiply by 100. Lenders use it as a quick measure of how much room you have to take on a new loan — a lower DTI means more of your income is free and you are a lower-risk borrower.
Divide your total required monthly debt payments by your gross monthly income and multiply by 100. If you pay $2,000 a month toward debts and earn $6,000 a month before tax, your DTI is 2,000 ÷ 6,000, or about 33%. Use gross income — before taxes and deductions — because that is the figure lenders use, not take-home pay.
Front-end DTI counts only your housing costs — rent, or a mortgage including principal, interest, taxes, and insurance — divided by gross income. Back-end DTI counts all monthly debt (housing plus car loans, student loans, card minimums, and other loans) divided by income. Lenders look mainly at the back-end number, but the 28/36 rule sets targets for both: 28% front-end and 36% back-end.
As a general guide, a back-end DTI of 36% or lower is healthy and matches the 28/36 rule. Fannie Mae allows up to 45% on manually underwritten loans when credit score and reserve rules are met, and up to 50% for loans approved through its Desktop Underwriter system. Above 50% is very high, and Fannie Mae will not buy a conventional loan with a ratio that high. In Canada, lenders look at GDS and TDS instead.
The 28/36 rule is a budgeting guideline lenders use: spend no more than 28% of gross monthly income on housing (front-end DTI) and no more than 36% on total debt including housing (back-end DTI). Staying within these limits signals your budget can comfortably absorb the payment, which is why many conventional loan programs use it as a benchmark.
Fannie Mae, which buys many US conventional loans, allows a total DTI of up to 36% on manually underwritten loans, up to 45% when credit score and reserve rules are met, and up to 50% for loans approved through its Desktop Underwriter system. The 43% figure you may see online was the old federal limit for a general qualified mortgage. The CFPB replaced it with a price-based test that took effect on March 1, 2021, and became mandatory on October 1, 2022. Other loan programs and lenders set their own limits, so check with your lender.
GDS (Gross Debt Service) and TDS (Total Debt Service) are the ratios Canadian lenders use instead of front-end and back-end DTI. GDS is your mortgage payment, property taxes, heating and 50% of any condo fees, divided by gross income. TDS adds all your other debt payments. For insured mortgages, CMHC limits GDS to 39% and TDS to 44%, and the mortgage payment is worked out at the greater of your contract rate plus 2% or 5.25%. Choose Canada as the country in this calculator to see both ratios.
Include the required monthly payments lenders see on your credit report: rent or mortgage (with taxes and insurance), car loans and leases, student loans, personal loans, minimum credit-card payments, and court-ordered payments like child support or alimony. Do not include utilities, groceries, phone bills, subscriptions, insurance premiums, or taxes — those are not treated as debts in the ratio.
Yes. Your current housing payment — rent or mortgage — is part of your DTI and forms the front-end ratio. When you apply for a mortgage, the lender replaces your current rent with the proposed new mortgage payment (with taxes and insurance) to calculate the DTI you would have with the new loan. In this calculator, enter your current or expected housing payment in the housing field.
Two levers: reduce monthly debt payments or raise gross income. Pay down high-balance credit cards to cut the minimums that count in the ratio, avoid new loans before a big application, and consider refinancing or consolidating to lower a payment. On the income side, a raise, second income, or documented side income all reduce DTI. Even paying off one small loan can move the ratio noticeably.
No — credit scores do not include your income, so DTI is not a direct factor. But the two are related: high card balances raise both your DTI and your credit utilization, and utilization is a major scoring factor. Lenders review DTI separately from your score during underwriting, so you can have an excellent score and still be declined if your DTI is too high, or vice versa.
The calculator uses the same formula lenders use — total monthly debt payments divided by gross monthly income — so the front-end and back-end percentages are accurate for the numbers you enter. The main source of difference is what you include: lenders pull required payments from your credit report and use gross income, so results match best when you enter gross (pre-tax) income and only the debts that appear on a credit report. All math runs in your browser and nothing you enter is stored or transmitted.
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