The Amortisation Calculator generates detailed payment schedules showing how each payment splits between principal and interest over the life of a loan. It supports four modes: full amortisation schedule, extra payment impact analysis, payoff date calculation, and total interest comparison.
Enter your loan details to see a month-by-month or year-by-year breakdown. The extra payment mode shows how additional payments can reduce your total interest and shorten the loan term.
Your calculations will appear here
An amortization schedule breaks down each monthly payment into its principal and interest components. Early in the loan, most of each payment covers interest. Over time, the interest portion shrinks and the principal portion grows as the outstanding balance decreases.
For each month, the interest portion equals the remaining balance multiplied by the monthly rate: Interest = Balance * (rate / 12). The principal portion is the monthly payment minus the interest: Principal = Payment - Interest. The new balance is the previous balance minus the principal paid.
Extra payments go entirely toward reducing the principal, which decreases future interest charges. Even modest extra payments can save thousands in interest and shorten the loan by months or years.
The total interest paid over the life of a loan can be substantial. On a 30-year mortgage, total interest often exceeds the original loan amount. The amortization table makes this cost visible and helps borrowers make informed decisions.
Problem: For a 200,000 loan at 6% over 30 years, what is the first month breakdown?
Solution: Monthly payment = 1,199.10. First month interest = 200,000 * 0.005 = 1,000. Principal = 1,199.10 - 1,000 = 199.10.
Answer: Month 1: 1,000 interest, 199.10 principal, balance 199,800.90
Problem: On a 250,000 loan at 5% over 30 years, how much does an extra 200/month save?
Solution: Without extra: 360 months, total interest 233,139. With extra: approximately 282 months, total interest 173,684.
Answer: Save approximately 59,455 in interest and pay off 6.5 years early
Problem: A 150,000 loan at 4.5% for 20 years starting January 2026. When does it pay off?
Solution: 20 years * 12 = 240 payments. January 2026 + 240 months = January 2046.
Answer: Payoff date: January 2046
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