Loan amortization calculator

Work out the equal monthly payment on a loan where interest is charged on the declining balance, and see the full schedule — how much of each payment is interest, how much is principal, and what is left afterwards. Rates here are monthly, which is how loans between people are almost always agreed.

Monthly amortization calculator

Nothing is sent anywhere — the whole calculation runs in your browser.

Amount lent

Currency

Term (months)

1 to 360 months.

Interest rate (% per month)

Monthly, not annual. Leave empty for an interest-free loan.

Monthly payment: $945.60
Last payment: $945.55
Total interest: $1,347.15
Total repaid: $11,347.15

Repayment schedule: payment, interest and remaining balance for each month.
Month	Payment	Interest	Balance after
1	$945.60	$200.00	$9,254.40
2	$945.60	$185.09	$8,493.89
3	$945.60	$169.88	$7,718.17
4	$945.60	$154.36	$6,926.93
5	$945.60	$138.54	$6,119.87
6	$945.60	$122.40	$5,296.67
7	$945.60	$105.93	$4,457.00
8	$945.60	$89.14	$3,600.54
9	$945.60	$72.01	$2,726.95
10	$945.60	$54.54	$1,835.89
11	$945.60	$36.72	$927.01
12	$945.55	$18.54	$0.00

How the payment is worked out

Amortization solves for the one payment size that clears the loan exactly at the end of the term. Interest is charged each month on what is still owed, so as the balance falls the interest share of each payment falls with it and the principal share grows. The payment itself never changes.

$10,000 over 12 months at 2% per month

Every payment is $945.60, except the last, which is $945.55 — five cents lower, absorbing the rounding so the balance lands exactly on zero.
Month 1: $200.00 of it is interest (2% of $10,000.00), leaving $9,254.40 owed.
Month 2: only $185.09 is interest, because the balance is smaller. More of the same payment goes to principal.
Over the year: $1,347.15 in interest, $11,347.15 repaid in total.

When amortization is the right choice

The borrower budgets monthly. One unchanging figure is far easier to plan around and to remember than a payment that moves every month.
You want the arithmetic to be uncontroversial. It is the plan people already recognise from mortgages and car loans, so it needs the least explaining.
The term is more than a few months. Over one or two months the plans barely differ; over a year the choice is worth real money.

It is not the cheapest of the six. Diminishing balance costs $1,300.00 in interest on the same terms against $1,347.15 here, because it repays principal faster. You are paying about $47.15 over the year for the convenience of a level payment — a trade worth making for many borrowers, but worth making knowingly.

Paying more than the scheduled amount

On an amortizing loan, extra money comes off principal, so it stops accruing interest immediately and the loan finishes early. The payment size stays the same; the number of payments falls. How overpayments are applied covers the order the money is allocated in and what changes on each plan.

What this calculator does not do

It assumes every payment arrives in full and on time. Missed payments accrue interest under separate rules.
It has no fees, insurance or one-off charges built in. Add those separately — in LoanCompass they are recorded as charges, which never compound.
It is arithmetic, not advice. Whether a rate is fair, lawful where you live, or wise to charge someone you know is outside what any calculator can tell you.

Keep reading

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