Amortization Schedule Calculator
Generate a complete month-by-month or year-by-year loan amortization table showing exactly how each payment is split between principal and interest — with optional extra payment analysis.
Applied entirely to principal each month.
Understanding Your Amortization Schedule
An amortization schedule is a complete table of every loan payment, showing exactly how much goes toward interest and how much reduces your principal balance.
Why So Much Goes to Interest Early
In a standard fixed-rate mortgage, each payment is the same dollar amount — but the split between principal and interest shifts dramatically over time. Early payments are overwhelmingly interest because the balance is highest; as the balance shrinks, the interest portion shrinks with it.
Example on a $300,000 loan at 7% for 30 years:
- Month 1: ~$1,750 interest / ~$245 principal
- Month 180 (year 15): ~$1,275 interest / ~$720 principal
- Month 360 (final): ~$13 interest / ~$1,982 principal
This is why extra payments made early in a loan have the greatest impact — they eliminate future interest charges on that principal.
The Power of Extra Payments
Adding even a small extra payment each month directly reduces your balance and cuts future interest charges. The earlier you start, the greater the effect.
| Extra Payment | Interest Saved (30-yr, $300k, 7%) | Years Saved |
|---|---|---|
| $0 | Baseline | — |
| $100/mo | ~$27,000 | ~3.5 years |
| $250/mo | ~$57,000 | ~7 years |
| $500/mo | ~$96,000 | ~11 years |
Amortization vs. Interest-Only Loans
A standard amortizing loan pays down principal every month. An interest-only loan requires no principal paydown during the interest-only period — your balance stays the same. After the interest-only period ends, payments jump significantly to repay the principal over the remaining term.
Frequently Asked Questions
Can I use this for auto loans, student loans, or personal loans? Yes — the amortization math is identical for any fixed-rate installment loan. Just enter the loan amount, rate, and term. If you need to figure out what loan amount your budget supports before running the schedule, the Mortgage Payment Calculator lets you start from home price, down payment, and rate to arrive at a payment figure first.
What does "fully amortized" mean? A fully amortized loan is completely paid off at the end of the term with no balloon payment. All standard fixed-rate mortgages are fully amortized.
Why is there a small rounding difference in the final payment? Amortization involves compounding arithmetic that accumulates small rounding differences. The final payment is usually a few cents different than the rest.
