Enter loan details to generate a complete amortization schedule with optional fees, prepayments, and a one-time lump sum.
Sample scenario (for reference): 10,000 loan, 9.000% APR, 3 years, monthly payments, 2% fee financed, no extras.
| # | Date | Payment | Interest | Principal | Balance |
|---|---|---|---|---|---|
| 1 | 2026-03-15 | $318.00 | $76.50 | $241.50 | $9,958.50 |
| 2 | 2026-04-15 | $318.00 | $74.69 | $243.31 | $9,715.19 |
| 3 | 2026-05-15 | $318.00 | $72.86 | $245.14 | $9,470.05 |
| 4 | 2026-06-15 | $318.00 | $71.03 | $246.97 | $9,223.08 |
| 5 | 2026-07-15 | $318.00 | $69.17 | $248.83 | $8,974.25 |
| 6 | 2026-08-15 | $318.00 | $67.31 | $250.69 | $8,723.56 |
The scheduled payment for a fully amortizing loan uses the standard PMT equation:
- P is the financed amount (loan plus financed fees, if selected).
- r is the periodic interest rate = APR ÷ payments per year.
- n is the total number of payments for the chosen frequency.
- Each row applies: Interest = Balance × r, then reduces principal by payment plus extras.
- Enter your loan amount, APR, and term (years and months).
- Select payment frequency and set your first payment date.
- Add optional fees, then choose whether to finance them.
- Use “Extra Payment” for consistent prepayments each period.
- Optionally apply a one-time lump sum on a chosen payment number.
- Press Calculate to see results above the form.
- Use the download buttons to export CSV or PDF schedules.
Payment structure and interest split
On a 15,000 loan at 10.5% APR over 36 monthly payments, the calculated installment is about 487.54. The first payment includes roughly 131.25 of interest and 356.29 of principal. Because interest is computed on the remaining balance, the interest portion shrinks each period while the principal portion grows, accelerating payoff late in the schedule.
Rate and term sensitivity
For the same 15,000 balance over 36 months, a 7% APR payment is about 463.16, while a 14% APR payment is about 512.66. Total interest is roughly 1,674 at 7% versus about 3,456 at 14%. With biweekly payments for 3 years (78 payments), the payment is about 224.57 and total interest is about 2,516 at 10.5%. Extending the term reduces the payment but typically increases lifetime interest, which the schedule quantifies clearly.
Fees and financed amount
Origination fees change what you really receive and what you repay. A 2% fee on 15,000 equals 300. If you finance that fee, the financed amount becomes 15,300 and the payment rises to about 497.29. If you pay the fee upfront, the financed amount stays 15,000, but net proceeds may be 14,700 and the fee may not earn interest.
Prepayments and payoff timing
Extra payments go directly to principal after interest. Adding 50 consistently per month increases the payment to about 537.54, shortens payoff to about 33 payments, and reduces interest from about 2,551 to about 2,273, a savings near 279. A one-time 1,000 lump sum on payment 6 can cut payoff to about 34 payments and save about 289 in interest.
Turning outputs into decisions
Use the amortization table to set checkpoints: balance after 12 payments, cumulative interest, and remaining payments. The chart highlights how quickly principal declines under prepayment plans. Export CSV to filter by year, sum interest, and compare scenarios side by side. Export PDF when you need a schedule for documentation, budgeting discussions, or lender conversations. If you enable rounding, totals may differ by a few cents.
How is the scheduled payment calculated?
The calculator uses a standard amortization payment formula. It converts APR to a periodic rate, sets the payment count from your term and frequency, then computes a fixed payment that reduces the balance to zero.
What does “extra payment” do?
Extra payment is added to principal after interest each period. Your scheduled payment stays the same, but the effective payment rises, the balance falls faster, and the payoff date usually moves earlier.
How are origination fees treated?
You can finance fees or pay them upfront. Financing increases the starting balance and payment. Paying upfront keeps the balance lower, but reduces the cash you receive at the start.
What if my APR is 0%?
With a 0% rate, interest is zero. The payment becomes financed amount divided by the number of payments, and each payment reduces principal by the same amount.
Why do totals sometimes differ by a few cents?
If per-step rounding is enabled, interest and balances are rounded each period. Over many payments, small rounding differences can slightly change the final totals versus precision math.
Can I model a one-time lump sum?
Yes. Enter the lump sum amount and the payment number to apply it. The schedule will apply that extra principal reduction on that payment and recompute payoff timing naturally.