What is the 28/36 rule?

The 28/36 rule states that housing costs should not exceed 28% of gross monthly income (front-end DTI) and total debt payments should not exceed 36% (back-end DTI). Most conventional lenders use these thresholds.

How is the maximum loan calculated?

The tool derives the maximum monthly payment from whichever DTI limit is tighter — 28% of income for housing alone, or 36% minus existing debts for total obligations — then back-solves using the standard amortization formula.

What counts as existing monthly debts?

Include all recurring debt obligations: car payments, student loans, credit card minimum payments, personal loans, and any other installment or revolving debt. Do not include utilities or subscriptions.

How accurate is the rent vs buy comparison?

The comparison is a simplified estimate. It adds 1% of the purchase price annually for maintenance and does not model property appreciation, tax deductions, or opportunity cost of the down payment.

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Loan Affordability Calculator

Find the maximum loan you can afford based on your income, debts, and the 28/36 rule.

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About this tool

Calculate how much you can borrow based on your monthly income and existing debts. Uses the standard 28% housing-expense ratio (front-end DTI) and the 36% total-debt ratio (back-end DTI) lenders apply when approving mortgages and personal loans. Enter your income, current monthly obligations, desired term, and interest rate to get the maximum affordable loan amount, estimated monthly payment, total cost of borrowing, and your resulting debt-to-income ratio. Also displays a 12-month amortization schedule and a rent-vs-buy comparison that weighs your prospective mortgage (plus typical maintenance costs) against a monthly rent figure you provide.

How to use

1 Enter your gross monthly income and the sum of all existing monthly debt payments.
2 Set the loan term in years and the annual interest rate.
3 Read the maximum affordable loan and the resulting monthly payment.
4 Scroll down to see the 12-month amortization breakdown (principal vs interest each month).
5 Enter a monthly rent figure in the Rent vs Buy section to compare total costs over the loan term.

Frequently Asked Questions

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