Amortization Calculator

About the Amortization Calculator

An amortization calculator generates a complete payment-by-payment schedule for any loan, showing exactly how each payment is split between principal and interest over the entire loan life. This detailed view of your loan is invaluable for tax planning (mortgage interest is often deductible), understanding your equity growth, and deciding whether and when to make extra payments. Every homeowner, car loan holder, and student loan borrower benefits from understanding their amortization schedule.

How It Works

Each monthly payment is constant, but its composition changes over time. In month 1, your payment is mostly interest. In the final months, nearly all of it is principal. Specifically, monthly interest = remaining balance × monthly rate. Principal paid = total payment − interest. New balance = old balance − principal paid. This cycle repeats for every month of the loan. On a 30-year mortgage at 6.5%, you don't reach the 50% equity mark until roughly year 20 — a fact many homeowners don't realize.

Tips & Best Practices

• ✓The first payment on a 30-year mortgage at 6.5% is about 85% interest, 15% principal.
• ✓Making one extra payment per year reduces a 30-year mortgage to roughly 25 years.
• ✓Bi-weekly payments (26 half-payments per year) equal 13 full payments instead of 12.
• ✓Lump-sum extra payments reduce your balance immediately and save future interest.
• ✓Mortgage interest deduction in the USA applies to interest, not principal — your schedule shows exactly how much.

Who Uses This Calculator

Tax preparers use amortization schedules to calculate deductible mortgage interest. Homeowners use it to plan lump-sum paydowns. Real estate investors use it to model cash flows and equity building across multiple properties. Our interactive schedule shows every one of the 360 monthly payments on a 30-year mortgage.