DTI Calculator (Debt to Income Ratio)
Front-end and back-end DTI plus mortgage verdict.
What it does
Debt to income ratios compress obligations into two percents lenders trust: housing costs over income up front, all monthly debts over income at the back. Both use gross monthly income as the base.
The tool above takes income with housing and other debts. It returns both ratios with a verdict against the 36 and 43 guides.
Qualified mortgages cap near forty three percent back end, which is why preapprovals die there regardless of credit scores. Front ratios near twenty eight keep the housing slice comfortable inside it.
Minimum payments count, not balances. A large idle credit line barely moves DTI while its minimum does, which is how paydowns target ratios efficiently.
How to use
- Enter gross monthly income before tax.
- Enter full housing cost with tax, insurance, HOA.
- Enter other minimum debt payments.
- Read both ratios against 28/36/43.
Formula
- housing
- PITI plus HOA dues monthly.
- other
- Minimums on recurring debts.
- 43%
- Qualified mortgage back end ceiling.
Auto leases, alimony, and child support count as debts when they run past ten months. Utilities and insurance do not.
Worked example
Example: $8,000 income, $2,000 housing, $500 debts
Income 8,000, housing 2,000, other debts 500.
- Front: 2,000 / 8,000 = 25%.
- Back: 2,500 / 8,000 = 31.25%, shown as 31.3%.
- Verdict: under 36%, good.
- Headroom to 43%: 0.43 x 8,000 - 2,500 = $940 more monthly debt allowed.
Reference table
| Back ratio | Verdict | Mortgage room |
|---|---|---|
| Under 20% | Excellent | Wide open |
| 20-36% | Good | Comfortable |
| 36-43% | Acceptable | Tight, near cap |
| Over 43% | High | Qualified loans unlikely |
Limits
- Minimums assumed. Actual payoff behavior differs.
- Gross income flatters versus net reality.
- Credit, reserves, and history decide beside ratios.
- Self employed averaging follows lender rules.
Common mistakes
- Leaving HOA out of housing.
- Counting balances instead of minimums.
- Using net income against gross cutoffs.
- Opening credit before closing.
- Ignoring the front ratio while passing back.
Try it yourself
Quick checks. Answers sit tucked under each question.
Income 10,000, housing 3,000, debts 500?
Front 30%. Back 3,500/10,000 = 35%. Good.
Max debts at 43% on 10,000?
4,300 total. Minus 3,000 housing leaves $1,300 other.
Questions
What is a good DTI?
Under 36% back end. Under 20% is excellent.
Front vs back ratio?
Front is housing only. Back adds all monthly debts.
What is the 43% rule?
Qualified mortgages generally cap back end DTI near 43%.
How do I lower DTI fast?
Pay down minimums and avoid new debt. Raises help slower.
Do utilities count?
No. Only debt minimums and housing enter ratios.
Does DTI use gross or net?
Gross monthly income before tax, by lending standard.