| Year | Principal Paid | Interest Paid | Remaining Balance |
|---|
What This Calculator Estimates
A mortgage amortization schedule breaks down each payment over the life of a loan into its principal and interest components, showing how the proportion shifts over time — early payments are weighted more heavily toward interest, while later payments increasingly go toward principal, even though the total payment amount typically stays the same throughout a fixed-rate loan. Understanding this schedule helps clarify how extra payments toward principal can meaningfully reduce total interest paid and shorten the loan term.
Formula / Method Used
Monthly Payment = P × [r(1+r)^n] / [(1+r)^n − 1], where P is loan amount, r is monthly interest rate, and n is total number of payments. Each month, interest is charged on the remaining balance, and the rest of the payment reduces principal.
Worked Example
A $300,000 loan at 6.5% over 30 years has a monthly payment of about $1,896. In year 1, roughly $1,920 goes to principal and $20,830 to interest — the split gradually reverses as the balance declines.
How to Interpret the Result
The yearly table shows how slowly principal builds early in the loan. Making extra principal payments, especially in the early years, can meaningfully cut total interest paid over the life of the loan.
Common Mistakes
- Confusing the quoted monthly payment with total monthly housing cost (PITI).
- Assuming principal and interest split evenly every month.
- Not considering extra payments as a way to reduce total interest.
- Ignoring how refinancing resets the amortization clock.
Related Calculators
Mortgage Calculator · Refinance Calculator · Down Payment Calculator
Tips for a More Accurate Estimate
- Consider making extra principal payments early in the loan term for maximum interest savings.
- Review your amortization schedule to understand how much equity you're building at any point.
- Remember variable-rate loans have amortization schedules that can shift if rates change.
- Use amortization insight to decide whether refinancing makes sense at a given point in your loan.
- Factor in any prepayment penalties before making large extra principal payments.
Frequently Asked Questions
Why do early mortgage payments go mostly toward interest?
Interest is calculated on the outstanding balance, which is highest at the start of the loan, so a larger portion of early payments covers interest, with the principal portion growing over time as the balance decreases.
Does the total payment amount change over the loan term?
For a standard fixed-rate mortgage, no — the total payment stays the same each month, but the split between principal and interest within that payment shifts over time.
How do extra principal payments affect amortization?
Extra payments applied directly to principal reduce the outstanding balance faster, which reduces future interest charges and can significantly shorten the effective loan term, even with relatively small additional payments.
What's the difference between amortization and just tracking loan balance?
Amortization specifically shows the principal/interest split for each payment period, giving insight into how much of each payment builds equity (principal) versus covers the cost of borrowing (interest).
Does a variable-rate mortgage have the same predictable amortization?
No, variable-rate loans have amortization schedules that can shift if the rate changes, unlike a fixed-rate loan where the schedule is set for the entire term at the outset.
Last updated: July 2026