How much mortgage payment fits after we count the other debts?

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Illustrative image of household planner, calculator and house keys on a table — Illustrative image. Not a photo of the people in this scenario.

One scenario used $6,506 in monthly income and tested a 50% debt-to-income ratio, or DTI.

The starting math was simple. The important work was making sure the income and payments were the right ones.

A ratio gives us a place to start. It does not tell us what payment will feel comfortable.

Work backward from the income

Under those discussion assumptions:

Monthly income: $6,506
DTI being tested: 50%
$6,506 × 50% = $3,253 for total counted monthly obligations

The lender still needs to accept the income. And 50% is the assumption used here, not a promised limit for every borrower or program.

If other counted debts were $879 a month, that would leave $2,374 for housing. That is a teaching comparison using debts from a separate discussion, not an approved payment for the same borrower.

Paying debts can create room and use up cash

In the separate payoff discussion, three accounts looked like this:

Balance $29,623: payment $484 per month
Balance $18,635: payment $308 per month
Balance $8,779: payment $87 per month
Total balances: $57,037
Total monthly payments: $879

Paying those debts could affect qualification if the program accepts that treatment. It also uses money that might otherwise go toward the borrower's goal.

I want to see both the monthly room gained and the cash left after the payoffs. Other accounts still need to be included too.

Housing means more than principal and interest

Property taxes, homeowners insurance, mortgage insurance, association dues and any retained first-mortgage payment need to be handled correctly.

Only then can we work out what payment is available for the new loan.

In another HELOC discussion, I pointed out that taxes and insurance were already included in the first-mortgage payment. Adding them again could overstate housing costs.

Check the statement against the worksheet. Count each required item once, and keep separately paid expenses in the total.

Put the full decision on one page

Verify the qualifying income.
List every debt and its required payment.
Show proposed payoffs and the cash they use.
Include the complete housing expenses.
Calculate the cash left for the actual goal.
Compare the payment with the household's comfort level.

A larger loan is not useful just because it fits a ratio. It needs to leave enough money for the reason you borrowed and a payment you can live with.

This example is based on a real mortgage discussion with identifying information removed. Any numbers are illustrative and are not current loan terms or a commitment to lend. Loan programs, rates, property values and borrower qualification vary.

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