Amortization Schedule Calculator

Amortization splits every fixed payment into interest and principal using three lines of arithmetic per month: interest equals the outstanding balance times the monthly rate, principal is what remains of the payment, and the balance drops by exactly that principal. Example: a 250,000 loan at 7% for 30 years has a fixed payment of ≈1,663.26; payment one charges 250,000 × 0.0058333 ≈ 1,458.33 of interest, leaving only 204.93 of principal. By year 5 the balance is near 235,500 and the principal share has grown to about 288; the lines cross around year 19–20 when principal finally exceeds interest. Adding 100 of extra principal every month from day one removes roughly 6 years and about 79,000 of interest from the schedule.

1. 1

   Step 1

   Enter loan amount, annual rate and term to compute the fixed payment.

2. 2

   Step 2

   The tool iterates month by month: interest = balance × rate ÷ 12.

3. 3

   Step 3

   Principal = payment − interest; the balance reduces by that amount.

4. 4

   Step 4

   Add extra monthly principal to see the schedule compress.

• Assuming equal splits

• Recasting after extra payments

• Ignoring rate resets