Mortgage Calculator
Estimate the full monthly cost of a home — principal, interest, property tax, and insurance — not just the loan payment.
Your numbers
US average is roughly 1.1% of the home's value per year, but it varies widely by state and county.
Your result
Excludes PMI, closing costs, and maintenance. With less than 20% down, most lenders add private mortgage insurance until you reach 20% equity.
How a mortgage payment is calculated
Your monthly principal-and-interest payment is set by a standard amortization formula so that the loan is exactly paid off at the end of the term. Early payments are mostly interest; by the final years, they're mostly principal.
Monthly payment = L × r(1 + r)n ÷ ((1 + r)n − 1), where L is the loan amount, r is the monthly rate (annual rate ÷ 12), and n is the number of payments (years × 12). Tax, insurance, and HOA are then added on top.
The term choice is the biggest lever after price. A 15-year loan has a notably higher monthly payment than a 30-year loan on the same home, but typically costs less than half as much total interest — try switching the term above to see the trade-off on your numbers.
Frequently asked questions
How much house can I afford?
A common guideline is the 28/36 rule: housing costs (principal, interest, tax, insurance, HOA) under 28% of your gross monthly income, and all debt payments under 36%. Lenders vary, and a payment that's “approved” isn't always comfortable — leave room for maintenance, which averages 1–2% of the home's value per year.
Why is my first payment mostly interest?
Interest is charged on the outstanding balance, which is largest at the start. On a $340,000 loan at 6.75%, the first month's interest alone is about $1,913. As the balance falls, the interest share shrinks and more of each fixed payment goes to principal.
What is PMI and when does it go away?
Private mortgage insurance protects the lender when you put down less than 20%. It typically costs 0.5–1% of the loan per year, added to your monthly payment. On a conventional loan it can usually be removed once you reach 20% equity, and it drops off automatically at 22%.
Home Affordability Calculator
How much house can you actually afford? This uses the 28/36 debt-to-income rules lenders apply: housing costs under 28% of gross income, and all debts together under 36%.
Your numbers
Use minimum/required payments — the same figures a lender counts. Don't include rent, utilities, or groceries.
Your result
Lender guidelines, not a pre-approval. Many lenders allow higher ratios for strong credit, and a payment a lender approves can still be uncomfortable — keep room for maintenance (1–2% of the price per year) and the rest of your budget.
How the 28/36 affordability rules work
Lenders judge a mortgage with two ratios of your gross monthly income. The front-end ratio (28%) caps total housing costs — principal, interest, taxes, insurance, HOA. The back-end ratio (36%) caps housing plus every other required debt payment. Your budget is whichever cap is lower after subtracting your existing debts.
Max housing payment = min(28% × gross monthly income, 36% × gross monthly income − monthly debts). The calculator then works backward from that payment — subtracting tax, insurance, and HOA — to the largest loan and home price it supports at your rate.
Notice what moves the answer most: existing debts. Every $100/month of car or card payments removes roughly $100 of housing budget under the back-end rule, which is why paying off a car loan before house-hunting can raise your price range more than the same money added to the down payment.
Frequently asked questions
Do lenders really stick to 28/36?
It's the classic guideline, not a hard law. Conventional loans often allow a back-end ratio up to 45–50% with strong credit and reserves, and FHA loans differ again. Think of 28/36 as the comfort zone: approved above it doesn't mean affordable for your actual life.
Should I use gross or take-home income?
Lenders use gross (pre-tax) income, which is what this calculator uses so you can compare with their numbers. For your own budgeting, sanity-check the result against take-home pay: many households aim to keep housing near 30% of net instead.
Why did a lender pre-approve me for more than this?
Pre-approvals often use the most permissive ratio a program allows and don't see your full spending — childcare, saving goals, or a second car on its last legs. The gap between “approved” and “comfortable” is where house-poor happens; borrow the smaller of the two numbers.