Loan Amortization Calculator: Schedule & Interest Savings

Model Extra, Biweekly & Annual (Mortgages, Auto, Personal)

The Amortization Calculator shows your payment, payoff date, and a complete amortization schedule. Try annual payments, biweekly payments, and extra payments for mortgages, car loans, or personal loans. Compare baseline vs prepayment to see months saved and interest saved instantly.

What Is Amortization?

• Amortization is paying down a loan in regular instalments until the balance reaches zero.
• Each payment covers interest first, then principal; the schedule shows this split every period.
• Amortization is for assets you cannot touch, like patents or trademarks. Companies spread the cost of physical assets over time due to wear and tear.
• When you compare offers, use this tool with a monthly to annual APR calculator. This will help you turn rates and fees into one true cost number.

How to Read the Amortization Schedule

• Payment: amount due each period
• Interest: rate × current balance ÷ periods/year
• Principal: payment minus interest
• Cumulative totals: running sums of interest and principal
• Remaining balance: what’s left after each payment
• Early payments are interest-heavy; later payments are principal-heavy.
• Extra payments reduce the principal immediately, lowering future interest.
• To see all housing costs, use an early mortgage repayment calculator. This will show PITI next to the basic amortization view. If your goal is speed, an Early Mortgage Payoff Calculator focuses on term reduction and interest avoided.

Model Real-World Scenarios 

• Amortization calculator annual payments: one larger payment per year (useful for bonus/seasonal income).
• Biweekly payments: ~26 half-payments/year (about one extra monthly payment/year), trimming time and interest. You can add small extras for certain months, like months 1 to 24. You can also apply a one-time payment. The comparison view will show you the new payoff date and how much interest you save.
• Auto loan calculator with extra payments: Try adding $50 or $100 every month. You can also pay every two weeks or make a one-time payment after selling an old car.
• Interest-only loan calculator: first, plan for an interest-only phase. Then, see the increase when amortization starts. If you are considering a term or rate change, use an Auto Refinance Calculator. This will help you find break-even points and total savings.
• Interest-only loan amortization calculator: view the IO phase and the amortizing phase on one timeline for clarity.
• Reverse amortization calculator: simulate negative amortization when payments don’t cover all interest.
• Car loan extra payment calculator: quantify months saved and interest avoided on a vehicle loan.
• Qualify for a VA loan? Use our VA Funding Fee Calculator to estimate your one-time funding fee and total monthly payment, then compare VA vs. conventional side by side.

Example 

• “Example: A $300,000 loan at 6.50% for 30 years ≈ $1,896/mo (principal & interest only).”
• Change Example1 → Example (Extra Payments)

Formula & Spreadsheet Tips

Payment (PI) formula:

• Payment = P × r × (1 + r)^n ÷ [(1 + r)^n − 1]
• P = principal, r = periodic rate (annual ÷ 12 for monthly), n = total number of payments

Excel/Sheets:

• Payment: ==PMT(annual_rate/12, Total_Months, -principal)
• Splits: =IPMT(...) (interest) and =PPMT(...) (principal)

Tips for Better Results

• Enter a start date to find the exact payoff date.
• Try biweekly or annual cadences if income is lumpy.
• Re-run scenarios yearly; small early extras have the biggest impact.

Disclaimer

Estimates are educational and not financial advice. Verify the conditions with your lender.