Remaining balance by month
Amortization schedule
| Month | Principal paid | Interest paid | Remaining balance | Remaining balance |
|---|
How this amortization calculator works
This page calculates a standard fixed-rate amortization schedule. Each repayment is split between interest and principal, and the balance falls to zero by the end of the term if every scheduled payment is made.
The repayment formula uses the loan amount, the periodic interest rate, and the total number of payments. Once those inputs are fixed, the schedule is deterministic.
- Interest paid is the borrowing cost for that payment period
- Principal paid is the part that reduces the outstanding balance
- Remaining balance shows how much loan principal is still unpaid after each payment
Amortization formula
The standard repayment formula is:
Payment = P x [r(1+r)^n] / [(1+r)^n - 1]
Where:
- P = loan amount
- r = interest rate per payment period
- n = total number of payments
If the interest rate is 0%, the schedule becomes a straight-line principal reduction and repayment equals the loan amount divided by the number of payments.
Why amortization matters
An amortization schedule shows much more than the headline repayment. It reveals how quickly the balance falls, how much interest is front-loaded early in the term, and how expensive a longer loan becomes in total.
That makes amortization analysis useful when comparing two offers that look similar on a monthly basis but behave differently over the full life of the loan.
How term length changes the schedule
Shorter terms usually increase each repayment but reduce total interest because the balance is outstanding for fewer periods. Longer terms lower the periodic payment but keep principal outstanding for longer, which usually raises total interest paid.
- Shorter term: higher payment, lower total interest
- Longer term: lower payment, higher total interest
Payment frequency and amortization
This calculator supports monthly, fortnightly, weekly, quarterly, and annual repayment structures. Changing frequency changes both the size and timing of repayments, which can change the exact interest pattern across the schedule.
That makes payment frequency a structural variable, not just a cosmetic setting.
What this schedule does not include
The amortization model here assumes a fixed rate and regular payments with no extra fees or penalties layered into the cash flow.
- No origination or broker fees
- No insurance add-ons
- No balloon payment
- No early-settlement charges
- No rate resets or variable-rate periods
Frequently asked questions
What is an amortization schedule?
An amortization schedule is a payment-by-payment breakdown showing how much of each repayment goes to interest, how much goes to principal, and what balance remains after each period.
Why is more interest paid at the start of the schedule?
Interest is charged on the outstanding balance. At the start of the loan, that balance is highest, so the interest portion is larger. As principal is repaid, the balance falls and the interest charge declines.
Can two loans with the same monthly payment have different amortization patterns?
Yes. The same repayment can be produced by different combinations of amount, rate, and term. The amortization schedule shows whether the balance is reducing quickly or whether the payment is mainly servicing interest early on.
Does a longer term always mean a cheaper loan?
No. A longer term usually lowers the payment but increases total interest because the balance stays outstanding for longer.
How does payment frequency affect amortization?
Changing payment frequency changes the number of periods and the interest timing. That can slightly change total interest and definitely changes the shape of the repayment schedule.
Can I use this for mortgages, car loans, and personal loans?
Yes, as long as the borrowing follows a fixed-rate amortized structure with regular repayments. It is a general amortization engine, not a lender-specific disclosure calculator.
What happens if the interest rate is zero?
If the rate is zero, there is no interest layer. Each payment goes directly toward principal, so the loan amount is simply divided across the payment count.
Does this calculator include extra repayments?
No. This version models the scheduled repayment path only. Extra-payment scenarios need a separate overpayment or payoff model because they change the amortization pattern midstream.