Scheduled monthly payment
$1,847.15
Amortization Calculator
Generate a month-by-month amortization schedule for fixed-rate loans.
Key Terms (Click to expand)
Amortization schedule
A month-by-month breakdown of payment amount, interest, principal, and remaining balance.
Principal
The amount borrowed before interest charges.
Interest portion
The cost of borrowing for a payment period based on the outstanding balance.
Extra payment
Additional monthly amount applied directly to principal to shorten payoff and reduce interest.
Remaining balance
The unpaid principal after each monthly payment is applied.
Tool
Total interest
$364,974.58
Total repayment
$664,974.58
Estimated payoff
360 payments
Amortization detail breakdown
| Loan amount | $300,000.00 |
|---|---|
| Loan term (months) | 360 |
| Annual interest rate | 6.25% |
| Extra payment (monthly) | $0.00 |
| Interest saved | $0.00 |
Amortization schedule
Methodology
The calculator first computes the scheduled monthly payment, then iterates month-by-month:
M = P * [r(1 + r)^n] / [(1 + r)^n - 1]
- P = loan amount
- r = monthly interest rate (annual rate / 12)
- n = total number of months in the loan term
- Each row computes interest from current balance, applies principal, and updates remaining balance.
Worked Example
For a loan amount of $300,000 at 6.25% over 30 years, scheduled monthly payment is $1,847.15.
Assumptions and Limitations
- This schedule assumes a fixed interest rate and monthly payment cadence.
- Extra payment is modeled as recurring monthly principal prepayment.
- Actual servicer rules may apply payments differently or include additional fees.
FAQ
What is an amortization schedule?
It is a payment-by-payment breakdown showing how each installment splits into principal and interest.
Why is interest higher at the beginning?
Early payments are calculated on a larger balance, so interest portion starts higher and falls over time.
What happens if I add extra monthly payments?
Extra payments reduce principal faster, which can shorten payoff time and lower total interest.