Comprehensive Guide
Learn more in our Loans & Mortgage Guide.
How it works
loan affordability by income calculator takes your inputs and produces affordable loan amount, affordable monthly payment, total loan cost, total interest paid. Calculate exactly how much loan you can afford based on your income, existing debts, and desired payment. You provide 6 inputs: Monthly gross income (currency, in dollars) (default: 5000 dollars); Existing monthly debt payments (currency, in dollars) (default: 500 dollars); Target monthly loan payment (currency, in dollars) (default: 800 dollars); Loan interest rate (%) (percent, in percent) (default: 6 percent); Loan term (years) (number) (default: 5); Maximum DTI allowed (%) (percent, in percent) (default: 36 percent). The calculator returns 4 outputs: Affordable loan amount (a secondary output); Affordable monthly payment (the primary result); Total loan cost (a secondary output); Total interest paid (a secondary output). Loans and mortgages are amortized instruments where the split between interest and principal shifts every month. Understanding the total cost of borrowing — not just the monthly payment — is the difference between a sustainable debt load and one that erodes your net worth over time. This calculator reveals the full amortization picture. The underlying formula: Max new payment = (Income × Max DTI%) − Existing debt payments. Affordable loan = PMT × ((1+r)^n − 1) / (r(1+r)^n). With the default values, affordable monthly payment is computed from the interaction of every input field — change any one of them and the result updates immediately, so you can stress-test different scenarios without re-entering the whole form. Adjust the inputs to match your real financial situation. The defaults are realistic starting points, but every person's circumstances differ — your actual income, expenses, rates, and timelines will produce a different answer. Use the tool iteratively: start with the defaults, then change one variable at a time to see which factor has the largest impact on your outcome.Formula
Max new payment = (Income × Max DTI%) − Existing debt payments. Affordable loan = PMT × ((1+r)^n − 1) / (r(1+r)^n).
Tips
- Keep total debt payments below 36% of gross income.
- Conservative: target 28% or lower for housing-related loans.
- Factor in property taxes, insurance, and HOA for mortgage affordability.
- Your affordable amount is your maximum, not your target. Borrow less when possible.
Frequently asked questions
What is a safe debt-to-income ratio?
Below 28% for housing (front-end). Below 36% for all debt (back-end). Some lenders approve up to 43–50%, but this leaves little room for emergencies or lifestyle changes.
How much loan can I afford on $5,000/month income?
At 36% DTI: $1,800 total debt payments. If you have $500 in existing payments, new payment can be $1,300. At 6% for 5 years: approximately $75,000 loan.
How accurate are the calculator results?
The math is exact — the same formulas a financial professional would use by hand. The precision of the output depends entirely on how realistic your inputs are. Use your actual numbers rather than estimates when possible. The defaults are reasonable starting points, but your real income, rates, and timeline will produce a different result.