Mortgage Calculator
Calculate your monthly mortgage payment with taxes and insurance — principal & interest breakdown, total interest and payoff cost for 15- and 30-year loans.
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How Is a Mortgage Payment Calculated?
Your monthly principal & interest follows the amortization formula: M = P × r × (1 + r)ⁿ ÷ ((1 + r)ⁿ − 1), where P is the loan amount (home price minus down payment), r the monthly rate (APR ÷ 12) and n the number of months. On top of P&I, most lenders escrow property taxes and homeowners insurance, which this calculator adds to show your true monthly cost. A 20% down payment also lets you avoid private mortgage insurance (PMI) with most lenders.
Example: a $400,000 home with 20% down ($80,000) at 7% APR for 30 years gives a $320,000 loan and about $2,129/month in principal & interest — plus roughly $67,000 in interest over the first five years alone. Compare 15- vs 30-year terms here before you talk to a lender.
Frequently Asked Questions
How much house can I afford?
A common guideline is the 28/36 rule: housing costs (including taxes and insurance) under 28% of gross monthly income, and all debt under 36%. On a $8,000 monthly income that caps housing near $2,240/month — work backward with this calculator to find the matching price.
15-year vs 30-year mortgage — what is the real difference?
The 15-year payment is higher, but the interest saved is dramatic: on a $320,000 loan at 7%, the 30-year costs about $446,000 in interest while a 15-year at 6.5% costs about $182,000 — roughly $264,000 saved.
What does APR include?
APR reflects the interest rate plus certain lender fees, so it is slightly higher than the note rate. For payment estimates the note rate is used; APR is best for comparing offers between lenders.
Do taxes and insurance change my payment?
Yes. Lenders typically collect 1/12 of your annual property tax and homeowners insurance each month in escrow. They vary by county and coverage — enter your annual amounts to see the full monthly payment.
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