Amortization Calculator

Generate a full amortization schedule and see exactly how extra payments shorten your loan.

By the CalculateBright team · Updated · How we calculate

Schedule
  

    How to use the Amortization calculator

    1. Enter your numbers. Fill in loan amount, interest rate, term, extra payment / month, schedule.
    2. Read your results. Results update instantly. The headline shows the monthly payment; the breakdown and table below show the details.

    What is amortization?

    Amortization is paying off a loan with equal payments over time. Each payment covers that month’s interest first; the rest reduces principal. As the balance falls, the interest portion shrinks and more of each payment goes to principal.

    The formula

    M = P × r(1 + r)n ÷ [(1 + r)n − 1]
    Interestk = Balancek−1 × r  ·  Principalk = M − Interestk

    where M is the monthly payment, P the amount borrowed, r the monthly interest rate (APR ÷ 12) and n the number of monthly payments. Each month, interest is charged on the remaining balance and the rest of the payment reduces principal, so early payments are mostly interest and later payments are mostly principal.

    The power of extra payments

    Extra principal payments go straight to the balance, so every future month accrues less interest. On a $250,000, 30-year loan at 6.75%, an extra $200/month saves roughly $100,000 in interest and cuts the term by about 8 years.

    Worked example

    With these inputs: loan amount$250,000; interest rate6.75%; term (years)30; scheduleYearly.

    The calculator gives a monthly payment of $1,621.50. Other results: total interest$333,738, total paid$583,738, paid off in30 yr, payoff dateOct 2056.

    What your results mean

    The schedule shows how each payment splits between interest and principal, and your balance after every year. With extra payments, the interest saved and the shorter payoff time show what prepaying is worth to you.

    Tips

    • Even one extra payment a year can cut years off a 30-year loan.
    • Tell your servicer to apply extra money to principal, not future payments.
    • Prepaying early in the loan saves the most interest.

    Frequently asked questions

    What is an amortization schedule?

    A table of every loan payment showing how much goes to interest and how much reduces principal, plus the remaining balance.

    Why is most of my early payment interest?

    Interest is charged on the remaining balance, which is highest at the start. As the balance falls, more of each payment goes to principal.

    Do extra payments always go to principal?

    Usually, but confirm with your lender and label the payment “principal only.”

    Is biweekly the same as extra payments?

    Paying half your payment every two weeks makes 13 full payments a year, the same as one extra payment annually.

    Can I amortize any loan here?

    Any fixed-rate, fully amortizing loan: mortgages, auto loans, personal loans.

    Related calculators

    Mortgage calculator · Loan calculator · Refinance calculator · House Affordability calculator · All mortgage & housing calculators