Loan Calculator — Monthly Payment, Interest & Amortization
Loan Calculator
Estimate your payment, total repayment, total interest, and full amortization schedule.
Loan inputs
Amortization schedule
| Month | Payment | Principal | Interest | Balance |
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How loan amortization works
An amortizing loan spreads repayment across a fixed number of payments. Each payment includes both principal and interest, but the mix changes over time.
At the start of the loan, more of each payment goes toward interest because the outstanding balance is highest. As the balance falls, the interest portion declines and more of each payment reduces principal.
This is why even a modest extra monthly payment can reduce the total interest substantially and shorten the payoff period.
- Lower rates reduce borrowing cost but do not always lower payment if the term changes.
- Longer terms generally lower the monthly payment but increase total interest.
- Extra payments lower the balance faster and usually save significant interest.
- Amortization schedules help you see exactly how your monthly payment is allocated.
Frequently asked questions
How is the monthly payment calculated?
The standard installment-loan formula divides the loan into equal monthly payments using the loan balance, interest rate, and number of payments.
What is total interest?
Total interest is the amount paid above the original principal. It represents the cost of borrowing over the life of the loan.
Why does my payment change over time?
On an amortized loan, interest is recalculated on the remaining balance each month. As the balance drops, interest declines and more of the payment goes to principal.
Does an extra payment help?
Yes. Extra payments reduce the balance faster, which lowers the interest charged on subsequent months and shortens the payoff time.
Does a longer term always cost more?
Usually yes, because you make more payments and interest accrues over a longer period. The monthly payment may be lower, but the total borrowing cost is often higher.
Is this a guaranteed lender quote?
No. This calculator is an educational estimate and may differ from final lender terms due to fees, credit profile, rate type, and eligibility.