What the payment includes โ and what it doesn't
The figures above are the principal & interest (P&I) on the loan itself. Your real monthly housing cost โ lenders call it PITI โ also includes property tax, homeowners insurance, PMI if your down payment is under 20%, and any HOA dues. Those commonly add several hundred dollars a month on a $400,000 loan, so budget above the P&I number.
How the rate changes a $400,000 payment
On a 30-year $400,000 loan, each 1% on the rate moves the monthly payment by roughly $263.01 and tens of thousands of dollars over the full term โ which is why shopping lenders and locking a good rate matters so much. The table above prices the same loan across today's realistic range so you can see exactly where your quote lands.
15-year vs 30-year on $400,000
A 15-year $400,000 mortgage at 6.5% costs about $3,484.43 a month versus $2,528.27 on the 30-year โ higher cash flow, but the total interest falls from about $510,178 to $227,197. The 30-year keeps payments low and flexible; the 15-year is cheaper overall if you can carry the bigger payment.
Estimates for a fully-amortising fixed-rate loan, principal & interest only. Excludes property tax, insurance, PMI and HOA dues. Rates shown for illustration โ your actual rate depends on credit, term and market conditions. Not financial advice.