Student Loan Mortgage Calculator 2026 — Buying Power

How student loans cut your buying power

Lenders judge you on two ratios. The front-end ratio (28%) says your housing payment should stay under 28% of gross monthly income. The back-end ratio (36%) says ALL your monthly debts — housing plus student loans, car payments, and credit cards — should stay under 36%. Your maximum housing payment is whichever limit is lower. A student loan payment only hurts your buying power when the back-end ratio is the binding one — which is exactly the case for most borrowers carrying both student debt and other debts.

Worked example: $60,000 salary, $400/month student loan

Gross monthly income $5,000. Front-end limit: $1,400. Back-end limit: $1,800. With a $400 student loan payment and $500 of other debts, the back-end allows $1,800 − $400 − $500 = $900 for housing. Without the student loan, it allows $1,800 − $500 = $1,300 (under the $1,400 front-end cap). The $400 difference, at 6.5% over 30 years with 10% down, 1.10% tax, and $1,800/year insurance, is worth about $60,600 of home price ($113,500 with the loan vs $174,100 without it). That is the true price of the student loan: not $400 a month, but sixty thousand dollars of house.

How each loan program counts student debt in 2026

The Fannie Mae $0 rule is why the same borrower can qualify for far more house with a conventional loan than with FHA while on an income-driven repayment plan. Ask your lender which program they are underwriting before you assume your student loan payment is fixed in stone.

Income-driven plans in 2026: SAVE ended, RAP replaced it

The SAVE plan ended in March 2026 and was replaced by the Repayment Assistance Plan (RAP), with a $10 minimum monthly payment. If you are on RAP or another income-driven plan, your documented payment is what matters for Fannie Mae — get that documentation from your servicer before you apply. And remember: a lower documented payment helps you qualify, but it does not reduce what you actually owe each month.

Ways to protect your buying power

Pay down high-payment debts before you apply; even a $200/month reduction can restore about $30,000 of buying power. If you are on an income-driven plan, keep your payment documentation current and ask lenders about Fannie Mae's $0-payment rule. And consider a larger down payment: it does not change your DTI ratios, but it lowers the loan amount you need for the same price, which can make an otherwise-tight payment fit.

Educational content only — not financial advice. Calculator results are estimates based on the inputs you enter. Actual loan terms, rates, fees, and approval depend on your lender, credit profile, property, and location. Talk to a licensed loan officer before making a home-buying decision.