Loan Affordability Calculator

This calculator estimates what a payment would cost at a given amount. It does not tell you a lender will offer it. Lenders apply their own debt limits, credit requirements and income verification, and their answer is frequently lower.

• Front-end ratio - housing costs only (principal, interest, taxes, insurance) as a share of gross income. Conventional guidelines commonly cap this near 28%.
• Back-end ratio - all monthly debt obligations including housing, car loans, cards and student loans. Commonly capped near 36%, and up to 43% for qualified mortgages.
• Some loan types allow higher - FHA programmes permit substantially higher ratios, sometimes with compensating factors such as cash reserves or a larger down payment.
• Manual underwriting - when a file falls outside automated limits, a human decides, and the outcome depends on the strength of the whole application.

Note. Your own calculation should be stricter than the lender's ceiling. A maximum approved ratio is a limit, not a target - it leaves no room for a rate rise, a repair bill or a period of lower income.

1. Rate. The most powerful input. On $400,000 over 30 years, the difference between 6.0% and 7.0% is $266 a month - about $96,000 over the term.
2. Term. Extending from 20 to 30 years lowers the payment materially but raises total interest substantially.
3. Total existing debt. Every $100 of existing monthly obligation reduces borrowing capacity by roughly $12,500 at current rates - which is why clearing a car loan before applying can matter more than a small improvement in income.
4. Down payment. Reduces the amount borrowed and improves the ratios simultaneously.
5. Income stability and credit. Affect the rate offered, which feeds back into the payment you are testing.

Before committing, run the calculator at a higher rate than the one quoted. Mortgage rates move, and so do rates on any variable product.

A move from 6% to 8% adds $537 a month - about 22% more - on the same loan. If the budget only works at the quoted rate, it does not work.

• Build a buffer. Test the payment against income after tax, not gross - the gap is typically 20-30%.
• Hold back for maintenance. Budget 1% of the property value a year for a home, or set aside a realistic figure for a vehicle.
• Keep an emergency fund intact. Do not put every dollar of available capacity into the payment; six months of expenses should survive the purchase.
• Include the costs of moving and any immediate work, which are real and are not in the payment.

1. Reduce existing debt first. Clearing a $400 monthly obligation improves capacity more than most rate negotiations.
2. Raise the down payment - it reduces the amount borrowed and the ratios together.
3. Extend the term only as a last resort. It lowers the payment by raising total cost; treat it as an affordability fallback rather than a saving.
4. Improve credit before applying. Even a quarter of a percentage point on a large long-term loan is worth thousands.
5. Add a second income cautiously. Lenders may count it, but a budget that depends on both earners has no slack if one is interrupted.
6. Consider a less expensive target. The cleanest solution is usually a smaller amount rather than a more creative structure.