Mortgage Amortization Schedule Calculator
An amortization schedule shows exactly how a fixed-rate mortgage is paid off, month by month and year by year. This calculator takes a loan amount, an interest rate and a term, works out the level monthly payment with the standard formula, then walks the loan forward to the final payment. Each month it charges interest on the current balance, applies the rest of the payment to principal, and reduces the balance, building a complete picture of where your money goes. The result is a year-by-year table of how much principal and interest you pay and what you still owe at the end of each year, plus the total interest and the number of months to payoff. Early on, most of each payment is interest because the balance is large; over time the principal share grows and the balance falls faster. Enter your own loan amount, rate and term to see the full schedule for your situation and to understand the true lifetime cost of the loan. The figures here are principal and interest only and do not include taxes or insurance, which the US Consumer Financial Protection Bureau recommends budgeting for separately. Every number is computed deterministically, with a worked example that reconciles exactly to the schedule below.
Each mortgage payment splits between interest and principal. On a $300,000 loan at 6.5%, the first payment of $1,896.20 is $1,625.00 interest and $271.20 principal.
Annual amortization summary
Each row shows the principal and interest paid during that year and the balance still owed at year end, for the loan amount, rate and term above.
| Year | Principal paid | Interest paid | Ending balance |
|---|---|---|---|
| Enable JavaScript to see the full annual schedule. A static first-quarter schedule is shown below. | |||
Amortization formula
M = P * r * (1 + r)^n / ((1 + r)^n - 1)
For each month: interest = balance * r
principal = M - interest
new balance = balance - principal
r = annual rate / 100 / 12, n = years * 12
First find the level payment M with the standard mortgage formula. Then repeat the three steps above for every month: charge interest on the balance, apply the rest of the payment to principal, and reduce the balance. The balance reaches zero on the final payment.
Worked example
A 300,000 loan at 6.5% over 30 years has a monthly payment of 1,896.20 (r = 0.065 / 12 = 0.00541667, n = 360). Trace the first month:
- Interest (month 1) = balance * r = 300,000 * 0.00541667 = 1,625.00
- Principal (month 1) = M - interest = 1,896.20 - 1,625.00 = 271.20
- New balance = 300,000 - 271.20 = 299,728.80
- Repeat for all 360 months until the balance reaches zero
- Total interest over the loan = 382,633.47
Month 1 interest is 1,625.00, principal is 271.20 and the ending balance is 299,728.80. Over all 360 payments the total interest is 382,633.47. These are the calculator's default inputs, so the schedule and totals above match exactly.
First three months (static)
This fixed table shows the opening of the schedule for the default 300,000 loan at 6.5% over 30 years, so there is content even without JavaScript.
| Month | Interest | Principal | Balance |
|---|---|---|---|
| 1 | 1,625.00 | 271.20 | 299,728.80 |
| 2 | 1,623.53 | 272.67 | 299,456.12 |
| 3 | 1,622.05 | 274.15 | 299,181.97 |
Figures in US dollars. Method: US Consumer Financial Protection Bureau, Owning a Home.
Mortgage amortization calculator: frequently asked questions
What is an amortization schedule?
An amortization schedule is a table showing every payment over the life of a loan, split into the interest charged that month and the principal that reduces the balance. Each row also shows the remaining balance after the payment. It lets you see exactly how a fixed-rate loan is paid down, how much interest you pay in total, and how the split shifts from mostly interest early on to mostly principal near the end.
Why does the principal portion grow each month?
The monthly payment is level, but interest is charged on the outstanding balance. As you pay the balance down, the interest charged each month falls, so a larger share of the same level payment goes to principal. In the first month of a 300,000 loan at 6.5%, only 271.20 of the 1,896.20 payment reduces the balance; near the end almost all of it does.
How is each month's interest calculated?
Each month, interest equals the current balance multiplied by the monthly interest rate, which is the annual rate divided by 12. The principal portion is the monthly payment minus that interest. The new balance is the old balance minus the principal portion. Repeating this for every month from the first to the last produces the full amortization schedule shown on this page.
Does the schedule include taxes and insurance?
No. This schedule covers principal and interest only. Property taxes, homeowners insurance and mortgage insurance are often collected through an escrow account and added to your total monthly bill, but they are not part of loan amortization. The US Consumer Financial Protection Bureau recommends budgeting for those costs separately from your principal and interest payment.
Can extra payments change the schedule?
Yes. Any extra amount paid toward principal reduces the balance faster than scheduled, which lowers the interest charged in every later month and shortens the term. This calculator shows the standard schedule with no extra payments. To model the savings from paying more each month, use the extra mortgage payment calculator linked in the related tools.
Official sources
- Mortgage basics, amortization and the costs of owning a home: US Consumer Financial Protection Bureau, Owning a Home. As at 24 June 2026.
Reviewed by the CalculatorHub team, edited by James Graham, 24 June 2026. See our methodology. This is general information, not financial, tax, legal or investment advice.