Calculate Your Monthly Payment and Full Amortization Schedule
What is an amortized loan?
An amortized loan is a loan with fixed, regular payments where each payment covers both interest and principal. In the early part of the loan, a larger share of your payment goes to interest. Later, more of each payment goes toward reducing principal. Mortgages, auto loans, and many personal loans use this structure.
The practical benefit of amortization is predictability: your required payment stays the same (for fixed-rate loans), and the loan is fully paid off at the end of the term if you make every payment on time.
How this amortized loan calculator helps
This calculator does more than estimate a monthly payment. It also builds your full amortization schedule month by month. That means you can see exactly how much interest you pay over time, how fast your balance declines, and how much you can save by adding extra monthly payments.
- Estimate your required monthly payment
- See total payment and total interest over the life of the loan
- Test extra payments to reduce payoff time
- View payoff date and month-by-month balance details
The monthly payment formula
For a fixed-rate amortized loan, the standard payment formula is:
M = P × r × (1 + r)n / ((1 + r)n − 1)
- M = monthly payment
- P = principal (loan amount)
- r = monthly interest rate (annual rate ÷ 12)
- n = total number of monthly payments
If the interest rate is 0%, the payment is simply principal divided by number of months.
Why extra payments matter so much
Extra payments typically apply directly to principal. Because interest is calculated on the outstanding balance, reducing principal earlier shrinks future interest charges. Even modest extra payments can remove years from a long mortgage and save thousands in interest expense.
Example strategy
If your payment is $1,580 and you add $100 extra each month, you may cut several years from a 30-year loan, depending on rate and balance. Try multiple scenarios in the calculator and compare interest saved.
Tips for using loan results wisely
- Compare at least three rates from different lenders.
- Use realistic tax, insurance, and maintenance assumptions for home purchases.
- Check whether your lender has any prepayment restrictions.
- Maintain an emergency fund before making aggressive extra payments.
- Recalculate after refinancing to understand your new payoff timeline.
Common questions
Does this work for mortgages, auto loans, and personal loans?
Yes. Any fixed-rate installment loan with regular monthly payments can be modeled with this amortization calculator.
Are taxes and insurance included?
No. The calculator focuses on principal and interest. For a full housing payment, add property tax, homeowners insurance, and HOA dues separately.
Can I use this for biweekly payments?
This version calculates monthly payments. You can still simulate faster payoff by entering a monthly extra payment equivalent to your biweekly strategy.