Mortgage Amortization Calculator
Generate a full year-by-year and month-by-month amortization schedule with optional extra payments.
Inputs
Extra principal applied every month. Shortens the schedule.
Optional. Used to label months in the schedule.
Monthly Payment (P&I)
$2,212.24
Total Interest Paid
$446,406
Total Amount Paid
$796,406
Loan Amount
$350,000
Payoff in
360months
Time Saved by Extra Payments
0months
Step by step
Scheduled monthly payment (P&I)
pmt($350,000, 6.5% ÷ 12, 360 months)
= $2,212.24
Payoff timeline
= 30 years 0 months (360 payments)
Total interest cost
= $446,406
Total amount paid
360 × ~$2,212.24
= $796,406
Year-by-Year Summary
| Year | Total Payment | Principal | Interest | Remaining Balance |
|---|---|---|---|---|
| Year 1 | $26,546.86 | $3,912.04 | $22,634.82 | $346,087.96 |
| Year 2 | $26,546.86 | $4,174.04 | $22,372.82 | $341,913.93 |
| Year 3 | $26,546.86 | $4,453.58 | $22,093.28 | $337,460.35 |
| Year 4 | $26,546.86 | $4,751.84 | $21,795.01 | $332,708.50 |
| Year 5 | $26,546.86 | $5,070.08 | $21,476.77 | $327,638.42 |
Month-by-Month Schedule
| Month | Payment | Principal | Interest | Extra | Balance | Cum. Interest |
|---|---|---|---|---|---|---|
| Month 1 | $2,212.24 | $316.40 | $1,895.83 | $0.00 | $349,683.60 | $1,895.83 |
| Month 2 | $2,212.24 | $318.12 | $1,894.12 | $0.00 | $349,365.48 | $3,789.95 |
| Month 3 | $2,212.24 | $319.84 | $1,892.40 | $0.00 | $349,045.63 | $5,682.35 |
| Month 4 | $2,212.24 | $321.57 | $1,890.66 | $0.00 | $348,724.06 | $7,573.01 |
| Month 5 | $2,212.24 | $323.32 | $1,888.92 | $0.00 | $348,400.74 | $9,461.93 |
| Month 6 | $2,212.24 | $325.07 | $1,887.17 | $0.00 | $348,075.68 | $11,349.11 |
| Month 7 | $2,212.24 | $326.83 | $1,885.41 | $0.00 | $347,748.85 | $13,234.52 |
| Month 8 | $2,212.24 | $328.60 | $1,883.64 | $0.00 | $347,420.25 | $15,118.16 |
| Month 9 | $2,212.24 | $330.38 | $1,881.86 | $0.00 | $347,089.87 | $17,000.01 |
| Month 10 | $2,212.24 | $332.17 | $1,880.07 | $0.00 | $346,757.70 | $18,880.09 |
| Month 11 | $2,212.24 | $333.97 | $1,878.27 | $0.00 | $346,423.74 | $20,758.36 |
| Month 12 | $2,212.24 | $335.78 | $1,876.46 | $0.00 | $346,087.96 | $22,634.82 |
How it works
An amortization schedule shows how each payment splits between principal and interest. In the early years of a mortgage, the vast majority of each payment is interest — on a 30-year loan at 6.5%, more than 70% of the first payment is interest. As the principal balance falls over time, the interest portion shrinks and the principal portion grows. By the final payment, almost the entire amount is principal.
Formulas
Monthly payment
M = P × r(1+r)ⁿ / ((1+r)ⁿ − 1)
- P
- Principal
- r
- Monthly rate (annual ÷ 12)
- n
- Number of months
- M
- Monthly payment
Per-period interest
Interest in period k = Balance at start of period × Monthly rate
- B_{k-1}
- Balance at start of period
- r
- Monthly rate
Per-period principal
Principal in period k = Payment − Interest in period k
Schedule assumes a fixed interest rate throughout the loan term. Actual statements may vary due to payment timing, rounding and escrow adjustments.
Frequently Asked Questions
Why does so little of my early payment go to principal?
Because interest is charged on the full outstanding balance. At the start of a $350,000 loan at 6.5%, you owe $1,895.83 in interest in month 1 alone. Only the amount above that reduces the principal. As you pay down the balance, the monthly interest charge falls and more of each payment goes to principal.
What happens to the schedule when I make an extra payment?
Every extra dollar goes directly to principal, reducing the balance on which next month's interest is computed. This creates a compounding benefit: not only does the balance drop faster, but every subsequent payment contains slightly less interest and more principal. Even a single extra payment early in the loan has a ripple effect.
How do I read the cumulative interest column?
The cumulative interest column shows the total interest paid from the start of the loan through each month. This is useful for tax planning (if your mortgage interest is deductible) and for visualising the total cost of the loan at any point in time.
When does my equity reach 20% (80% LTV)?
Look at the balance column in the monthly schedule and find the row where the balance falls to 80% of your original purchase price. That is the month you can request PMI cancellation if you have a conventional loan.