📊 Amortization Schedule Calculator
By ToolNimba Finance Team · Reviewed by ToolNimba Editorial Review, personal finance content · Updated 2026-06-19
This calculator produces an estimate for a standard fixed-rate amortizing loan. Your real schedule can differ because of fees, escrow for taxes and insurance, the exact day-count and compounding convention your lender uses, and whether your rate is fixed or floating. The figures here are not financial advice, confirm the numbers in your loan agreement and speak to a qualified adviser before borrowing.
Yearly summary
Each row totals 12 monthly payments for that year. Use the button to expand the month-by-month detail.
| Year | Interest paid | Principal paid | Balance at year end |
|---|
An amortization schedule shows, month by month, how a loan gets paid off: how much of each payment goes to interest, how much goes to principal, and what balance is left. Enter the loan amount, annual interest rate and term in years, and this calculator works out the level monthly payment, then builds the full schedule. You get a year-by-year summary and can expand any year to see every monthly payment, so you can see exactly where your money goes over the life of the loan.
What is the Amortization Calculator?
Amortization is the process of paying down a loan with a series of equal payments, where each payment covers the interest due for that period and then chips away at the principal you still owe. Because the payment is level, the lender first solves for the single amount that will clear the loan to zero over the chosen term. That payment comes from the standard formula M = P·r·(1+r)^n ÷ ((1+r)^n − 1), where P is the principal, r is the monthly interest rate (annual rate ÷ 12 ÷ 100), and n is the total number of monthly payments.
The schedule itself is built one month at a time. For each month, the interest portion is the current balance multiplied by the monthly rate. Whatever is left of the fixed payment after that interest goes to principal, and the balance drops by that principal amount. The next month starts from the new, smaller balance, so its interest is a little lower and its principal a little higher. Repeat until the balance reaches zero, and you have the full amortization table.
The headline pattern is front-loaded interest. Early in the term the balance is large, so most of each payment is interest and very little reduces principal. As the years pass and the balance shrinks, the split flips: the interest portion shrinks and more of the same payment attacks the principal. This is why extra payments made in the first years of a long loan save far more interest than the same payments made near the end, and why building equity in a mortgage feels slow at first.
When to use it
- Seeing how a mortgage or auto loan splits between interest and principal over its full term.
- Checking how much equity you will have built after a given number of years.
- Comparing total interest across different terms before you lock in a loan.
- Estimating how much interest a prepayment could save by reading the balance and interest columns.
How to use the Amortization Calculator
- Enter the loan amount (the principal you are borrowing).
- Enter the annual interest rate offered by the lender.
- Enter the term in years.
- Read the monthly payment, total interest and total paid in the summary cards.
- Scan the yearly summary, then click Show months on any year to expand the month-by-month detail.
Formula & method
Worked examples
A $200,000 loan at 6% annual interest over 30 years (360 months).
- Monthly rate r = 6 ÷ 12 ÷ 100 = 0.005
- Number of payments n = 30 × 12 = 360
- (1 + r)ⁿ = 1.005^360 = 6.022575
- M = 200,000 × 0.005 × 6.022575 ÷ (6.022575 − 1) = 1,199.10
- Month 1 interest = 200,000 × 0.005 = 1,000.00, so principal = 1,199.10 − 1,000.00 = 199.10
- Total paid = 1,199.10 × 360 = 431,676.38, total interest = 431,676.38 − 200,000 = 231,676.38
Result: Payment ≈ $1,199.10 · Total interest ≈ $231,676.38 · Total paid ≈ $431,676.38
A $25,000 auto loan at 7% annual interest over 5 years (60 months).
- Monthly rate r = 7 ÷ 12 ÷ 100 = 0.0058333
- Number of payments n = 5 × 12 = 60
- (1 + r)ⁿ = 1.0058333^60 = 1.417625
- M = 25,000 × 0.0058333 × 1.417625 ÷ (1.417625 − 1) = 495.03
- Month 1 interest = 25,000 × 0.0058333 = 145.83, so principal = 495.03 − 145.83 = 349.20
- Total paid = 495.03 × 60 = 29,701.80, total interest = 29,701.80 − 25,000 = 4,701.80
Result: Payment ≈ $495.03 · Total interest ≈ $4,701.80 · Total paid ≈ $29,701.80
How the term changes the payment and total interest on a $200,000 loan at 6% annual
| Term | Monthly payment | Total interest | Total paid |
|---|---|---|---|
| 15 years (180 mo) | $1,687.71 | $103,788.46 | $303,788.46 |
| 20 years (240 mo) | $1,432.86 | $143,886.91 | $343,886.91 |
| 30 years (360 mo) | $1,199.10 | $231,676.38 | $431,676.38 |
Interest versus principal split inside the first payment, $200,000 at 6% over 30 years
| Payment | Goes to interest | Goes to principal |
|---|---|---|
| Month 1 | $1,000.00 | $199.10 |
| Month 180 (about year 15) | $712.92 | $486.18 |
| Month 360 (final) | $5.97 | $1,193.14 |
Common mistakes to avoid
- Thinking each payment splits evenly between interest and principal. It does not. Early payments are mostly interest because the balance is large, and only late in the term does most of each payment go to principal. The schedule makes this front-loading obvious.
- Choosing the longest term just for a smaller payment. A longer term lowers the monthly payment but you hold the balance for longer, so total interest climbs sharply. On a $200,000 loan at 6%, moving from 15 to 30 years more than doubles the total interest paid.
- Forgetting that the payment shown is principal and interest only. For a mortgage, your actual monthly bill usually also includes property tax, homeowners insurance and sometimes mortgage insurance held in escrow. The amortization payment here covers only the loan itself.
- Assuming a floating-rate schedule stays fixed. This schedule assumes a fixed rate for the whole term. If your rate is variable, every rate change reshuffles the remaining schedule, so treat the table as a snapshot at today’s rate.
Glossary
- Amortization
- Paying off a loan through equal periodic payments that each cover interest and reduce the principal until the balance reaches zero.
- Principal
- The amount still owed on the loan. The portion of each payment that reduces it is the principal portion.
- Interest portion
- The part of a payment that pays the lender for that period, equal to the current balance times the monthly rate.
- Amortization schedule
- The full table listing every payment with its interest, principal and remaining balance.
- Term
- The total length of the loan, here entered in years and converted to months as n in the formula.
Frequently asked questions
What is an amortization schedule?
An amortization schedule is a table that lists every payment over the life of a loan and breaks each one into the interest portion, the principal portion, and the balance remaining afterward. It shows exactly how the loan is paid down over time.
How is the monthly payment calculated?
The payment uses the standard formula M = P·r·(1+r)ⁿ ÷ ((1+r)ⁿ − 1), where P is the principal, r is the monthly rate (annual rate divided by 12 then by 100), and n is the number of months. It solves for the single level payment that clears the loan to zero.
Why is so much of my early payment interest?
Interest each month is the balance times the monthly rate. At the start the balance is at its largest, so the interest charge is high and only a little of the fixed payment is left for principal. As the balance falls, the interest portion shrinks and more goes to principal.
Does paying extra change the schedule?
Yes. Any extra amount goes straight to principal, which lowers the balance faster, reduces the interest charged in every later month, and shortens the loan. This calculator shows the standard schedule, but you can see the saving by comparing the interest column with and without a shorter term.
Does the payment shown include taxes and insurance?
No. The payment here is principal and interest only. For a mortgage your real monthly bill often also includes property tax, homeowners insurance and sometimes mortgage insurance, which lenders collect in an escrow account on top of the loan payment.
Why does the total interest get so large on long loans?
Because you owe the balance for more months, and interest is charged every month on whatever is still outstanding. A longer term gives a smaller payment but a much larger total interest bill, which is why the term is one of the most important choices when you borrow.
Sources
- Amortization , Investopedia
- What is amortization? , U.S. Consumer Financial Protection Bureau