Amortization Schedule
Generate a loan amortization preview with monthly payment, principal split, total interest, and payoff schedule. Client-side and private.
By Utilix Editorial Team · Added May 4, 2026 · Updated Sep 6, 2026
Input
Result
Enter a value for loan amount to see your result.
How it works
Builds a fixed-rate loan amortization preview showing the monthly payment, total interest, and how early payments split between principal and interest.
Formula
Payment = P x r / (1 - (1 + r)^(-n))
- P
- Loan principal
- r
- Monthly interest rate
- n
- Number of monthly payments
Step by step
- 01Convert the annual interest rate to a monthly rate.
- 02Calculate the fixed monthly payment from principal, monthly rate, and term.
- 03For each month, compute interest from the remaining balance.
- 04Subtract interest from the payment to find principal repaid, then reduce the balance.
Examples
$250,000 at 6.5% for 30 years
A 30-year loan starts interest-heavy; month 1 includes about $1,354 in interest and $226 in principal.
Inputs
- Loan amount:
- 250000
- Annual interest rate:
- 6.5
- Loan term:
- 30
Result
- Monthly payment:
- 1580.17
- Total interest:
- 318861.07
More about this tool
An amortization schedule breaks a fixed-rate loan into individual monthly payments and shows exactly how much of each payment goes toward interest versus principal. This calculator computes the fixed monthly payment first, then walks the balance down month by month:
Payment = P × r / (1 − (1 + r)^(−n))
Monthly Interest = Remaining Balance × r
Monthly Principal = Payment − Monthly Interest
New Balance = Remaining Balance − Monthly Principal
Why the Split Changes Every Month
Because interest is calculated on the remaining balance, the interest portion is largest in month 1 (when the balance is highest) and shrinks every month as the balance falls — while the principal portion grows to compensate, keeping the total payment fixed. On a 30-year mortgage, it's common for more than half the loan term to pass before principal exceeds interest in a single payment.
Reading the Preview Table
This tool shows the first 12 months plus the final month, since a full 360-row table (for a 30-year loan) rarely fits usefully on screen. To see every single month — useful for tax documentation, refinance comparisons, or a full payoff projection — use the branded PDF export, which includes a complete amortization appendix.
What's Not Modeled
Real lender statements include escrow (property tax and insurance collected monthly), rounding to the cent that can shift the final payment slightly, and partial first periods if your loan doesn't start on the first of the month. This calculator models the underlying math cleanly; treat small discrepancies with an actual lender statement as normal.
Pair this with the Extra Payment Payoff Calculator to see how additional principal payments compress this exact schedule and cut years off the loan.
Frequently asked questions
Why is early interest so high?
Interest is charged on the remaining balance, so the first payments have the largest interest portion.
Is this a full lender statement?
No. It models standard monthly amortization before fees, escrow, rounding rules, and partial first periods.
How can I get the full month-by-month schedule, not just the first year?
Use the branded PDF report (Export → Download PDF report) to generate a full amortization appendix covering every month of the loan term, not just the preview shown on screen.
What happens to the schedule if I make an extra payment?
This calculator shows the standard fixed schedule without extra payments. Use the Extra Payment Payoff Calculator to see how additional principal payments shorten your term and reduce total interest.
Does the schedule change if my rate is variable (ARM)?
No — this models a fixed rate for the full term. For an adjustable-rate loan, the schedule shown is only accurate until your rate resets; recompute with the new rate at each reset period.