LTV & DTI Calculator
Check the two ratios lenders care about (loan-to-value, and front-end and back-end debt-to-income) against the conservative 28/36 rule of thumb and Fannie Mae’s 36%/45%/50% DTI limits. Runs in your browser.
Loan-to-value
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Show the math
Lenders weigh two ratios when sizing a loan:
LTV = loan ÷ value
DTI = monthly debt ÷ gross income
28/36 (28% front-end for housing, 36% back-end for all debts) is a conservative rule of thumb, not a lending limit. For conventional loans, Fannie Mae's Selling Guide (B3-6-02) caps total DTI at 36% for manually underwritten loans, up to 45% if you meet its credit score and reserve requirements, and 50% through its automated Desktop Underwriter. FHA, VA, and other loans have their own rules, and PMI is typically required above 80% LTV. Treat these as a screen, not a decision. All math runs locally in your browser.
What this does
An LTV and DTI calculator checks the two ratios lenders weigh (loan-to-value, and front-end and back-end debt-to-income) against the conservative 28/36 rule of thumb and Fannie Mae’s published DTI limits.
How it works
LTV is the loan divided by the home’s value. Front-end DTI counts only housing costs against income; back-end DTI counts all monthly debt payments against income.
How to use it
- Enter the home value and loan balance.
- Enter your gross monthly income.
- Enter your housing payment (PITI) and other monthly debts.
- Read your LTV, DTI ratios, and how they compare with 28/36 and Fannie Mae’s limits.
Understanding your result
28/36 (28% of income for housing, 36% for all debts) is a conservative rule of thumb, not a lending limit. For conventional loans, Fannie Mae’s Selling Guide (B3-6-02) sets a maximum total DTI of 36% for manually underwritten loans, up to 45% if the borrower meets its credit score and reserve requirements, and 50% for loans run through its Desktop Underwriter. FHA, VA, and other programs set their own limits.
Example
$1,800 of housing plus $900 of other debts on $6,000 monthly income is a 30% front-end and 45% back-end DTI: over the 28/36 rule of thumb, but within Fannie Mae’s 45% manual-underwriting maximum if the credit score and reserve requirements are met, and within its 50% DU limit.
Sources & methodology
- CFPB, What is a debt-to-income ratio?, How DTI is figured and why lenders use it
Last updated .
Frequently asked questions
What is loan-to-value?
LTV is the loan balance divided by the home’s value. Above 80% usually means PMI; lower LTV generally means better loan terms.
What is the difference between front-end and back-end DTI?
Front-end DTI counts only housing costs against income; back-end DTI counts all monthly debt payments. The 28/36 rule of thumb keeps them at or under 28% and 36%.
What DTI do I need to qualify?
It depends on the loan program and lender. For conventional loans sold to Fannie Mae, the Selling Guide (B3-6-02) caps total DTI at 36% for manually underwritten loans, up to 45% with its credit score and reserve requirements, and 50% through Desktop Underwriter. Treat 28/36 as a conservative rule of thumb, not a hard cutoff.
Is my income data stored?
No. All calculations run locally in your browser.
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