Mortgage Rate Impact Calculator
Compare two mortgage interest rates to see the difference in monthly payment and total interest paid over the life of the loan.
Payment Difference
Monthly mortgage payment is calculated using the standard amortization formula:
M = P × [r(1+r)^n] / [(1+r)^n - 1]
Where:
- P = loan principal
- r = monthly interest rate (annual rate ÷ 12)
- n = total number of payments (years × 12)
Example: A $400,000 loan at 6% vs 7% over 30 years:
- At 6%: $2,398/mo → $863,353 total
- At 7%: $2,661/mo → $958,036 total
- Difference: $263/mo or $94,683 over the loan
Even a 0.25% rate difference on a $400,000 loan adds roughly $60/month and $20,000+ over 30 years.