LoanCalculatorTools

Loan Amortization Calculator

Build a payment-by-payment schedule for any instalment loan, with the principal and interest split and the payoff date.

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Free · No sign-up · Runs in your browser

A schedule answers questions a payment figure cannot: how much of this month goes to interest, what the balance will be in three years, and what an extra payment actually removes from the loan.

This calculator builds the full schedule with dates for any level-payment loan, and shows the effect of an extra monthly amount on both the interest total and the payoff date.

Your numbers

Results update as you type. Nothing is sent anywhere.

Result

Monthly payment

$525

Total interest

$6,503

Total paid
$31,503
Payments to clear
60 months
Payoff date
2031-03-01
Interest in payment 1
$197.92
Principal in payment 1
$327.13
Interest in the final payment
$4.12

Early payments are mostly interest because interest is charged on the outstanding balance. The principal share grows every month.

Servicers may round the final payment slightly differently, so the last row can differ by a few cents from a lender statement.

Payment-by-payment schedule

PaymentAmountPrincipalInterestBalance
1. 2026-04$525.05$327.13$197.92$24,673
2. 2026-05$525.05$329.72$195.33$24,343
3. 2026-06$525.05$332.33$192.72$24,011
4. 2026-07$525.05$334.96$190.09$23,676
5. 2026-08$525.05$337.61$187.43$23,338
6. 2026-09$525.05$340.29$184.76$22,998
7. 2026-10$525.05$342.98$182.07$22,655
8. 2026-11$525.05$345.69$179.35$22,309
9. 2026-12$525.05$348.43$176.62$21,961
10. 2027-01$525.05$351.19$173.86$21,610
11. 2027-02$525.05$353.97$171.08$21,256
12. 2027-03$525.05$356.77$168.27$20,899

How to use the loan amortization calculator

  1. Enter the loan amount, rate and term.
  2. Enter the first payment date to get dated rows.
  3. Add an extra monthly payment if you want the accelerated schedule.
  4. Expand the table to see every payment.

What people use this for

  • Finding the balance at a specific future date.
  • Seeing the interest split on any individual payment.
  • Testing how extra payments shorten a loan.
  • Checking a lender statement against the expected schedule.

Worked examples

Every figure below is produced by running this calculator against the example inputs, so the numbers always match the tool.

A five-year loan

$25,000 at 9.5% over 5 years, first payment April 2026.

Monthly payment
$525
Total interest
$6,503
Interest in payment 1
$197.92

The same loan with $150 extra

Identical terms with an additional $150 each month.

Total interest
$4,705
Payments to clear
45 months
Payoff date
2029-12-01

The split shifts every month

Interest is charged on the opening balance, so it falls every month while the payment stays the same. The principal portion rises to match, slowly at first and then quickly as the balance drops.

On a shorter loan at a moderate rate the crossover happens early - frequently within the first year - which is why five-year loans build equity far faster than thirty-year ones despite the higher payment.

Extra payments compound

An extra amount applied to principal removes not only that amount but every future month of interest it would have generated. On a high-rate loan the effect is considerably larger than the amount paid.

Confirm with the lender that extra funds reduce principal rather than being held as a prepaid future instalment. The two look similar on a statement and produce very different results.

Methodology and assumptions

What this calculator does, and what it deliberately does not do.

  • Each row charges interest on the opening balance at the periodic rate and applies the remainder to principal.
  • Extra payments reduce principal after interest is charged.
  • The final payment is normally smaller because only the remaining balance is due.
  • Results are estimates. Real quotes depend on credit, income, property, loan programme and lender pricing at the time of application.
  • Nothing you type is transmitted or stored - the calculation runs entirely inside your browser.

This calculator is provided for informational and educational purposes only. Results are estimates and may not reflect actual rates, fees, taxes, or market conditions.

This website is not a lender, a mortgage broker or a financial adviser. It does not originate loans, does not accept applications and does not forward your details to anyone.

Actual loan terms depend on credit history, income, the property, the loan programme and lender pricing at the time of application. Only a lender can tell you what you qualify for.

Frequently asked questions

Does this work for any loan type?

Any level-payment amortising loan - personal, auto, business or mortgage. Interest-only and balloon structures need their own calculators.

Why does my lender’s schedule differ slightly?

Rounding conventions and day-count methods differ. A few cents per payment is normal; larger gaps usually mean a different rate or term.

Can I model an irregular extra payment?

This models a consistent monthly amount. For a one-off lump sum, use a payoff or extra payment calculator instead.

Does the payment change if I overpay?

On most loans no - the term shortens instead. Some lenders will recast the payment on request after a large lump sum.

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