Mortgage Amortization Calculator
See the principal-vs-interest split and remaining balance for any single year of your mortgage.
How the calculation works
Simulates the loan month by month from the start, since interest is always calculated on whatever balance remains, then sums up the principal and interest paid across the 12 months of whichever year you select. Because the balance shrinks every month, more of each payment goes to principal and less to interest as the loan ages, so later years show a much higher principal share than early ones for the same fixed payment.
Formula
Each month: Interest = Balance × Monthly Rate. Principal = Payment − Interest. Balance = Balance − Principal. The selected year sums principal and interest across its 12 months.
Examples
$320,000 loan, 6.5% rate, 30-year term, year 1
$2,022.62/month; year 1: $3,576.72 principal, $20,694.69 interest; $316,423.28 remaining
$320,000 loan, 6.5% rate, 30-year term, year 15
$2,022.62/month; year 15: $8,863.94 principal, $15,407.48 interest; $232,189.25 remaining