How to use it
- Type the amount you borrow and the yearly interest rate from your loan offer.
- Enter the term and choose whether it is in years or months.
- To test paying the loan off faster, enter an amount in Extra payment every month.
- Read the monthly payment and the totals, then open the table to see each payment. Use Download as CSV to keep it in a spreadsheet.
How the payment is calculated
Most personal loans, car loans and mortgages are annuity loans: the payment is the same every month, and the share that is interest shrinks as the balance falls. The payment comes from the standard annuity formula.
Each month the interest is the balance multiplied by the monthly rate. The rest of the payment reduces the balance. Early payments are mostly interest; late payments are mostly principal.
M = P × r ÷ (1 − (1 + r)^−n)
M monthly payment
P loan amount
r monthly rate = yearly rate ÷ 12
n number of monthly payments- With a rate of 0% the payment is simply the amount divided by the number of months.
- Amounts are rounded to cents every month, as a lender does. The last payment clears whatever is left, so it can differ by a few cents.
What an extra payment does
An extra payment is taken off the principal at once. Next month's interest is charged on a smaller balance, so more of every later payment goes to principal. The loan ends sooner and the total interest is lower.
The calculator compares the schedule with and without your extra amount and shows the interest you save. Check your loan contract first: some lenders charge a fee for early repayment or limit how much you may overpay in a year.
What this calculator does not include
- Fees, insurance and taxes that a lender may add to the payment.
- Rates that change during the term. For a variable-rate loan, run the calculator again with the new rate and the balance left.
- Payment plans other than monthly, such as fortnightly payments.
Worked example: 200,000 at 6% over 30 years
The monthly rate is 6% ÷ 12 = 0.5%, and there are 360 payments. The formula gives a payment of 1,199.10.
In the first month the interest is 200,000 × 0.5% = 1,000.00, so only 199.10 reduces the balance. Over 30 years the interest adds up to about 231,677, more than the amount borrowed.
Paying 200 extra every month ends the loan after 21 years instead of 30, and the total interest falls to about 151,876: a saving of roughly 79,800.
| No extra payment | 200 extra a month | |
|---|---|---|
| Monthly payment | 1,199.10 | 1,399.10 |
| Number of payments | 360 | 252 |
| Total interest | 231,677.04 | 151,876.18 |
Frequently asked questions
What is an amortization schedule?
It is the list of every payment of a loan. For each payment it shows how much is interest, how much repays the principal and what balance is left afterwards.
Why is so much of my early payment interest?
Interest is charged on the balance, and the balance is highest at the start. In the example above, 1,000.00 of the first 1,199.10 payment is interest. By the last year almost the whole payment is principal.
Is the rate here the same as the APR?
No. Enter the nominal interest rate of the loan. The APR also spreads fees over the term, so it is usually higher and would overstate the payment.
Is it better to shorten the term or to pay extra each month?
The effect on interest is the same if the amounts are the same. Paying extra keeps the required payment low and leaves you free to stop; a shorter term usually comes with a lower rate but a payment you must make every month.
Can I use it for a car loan or a student loan?
Yes, for any loan with a fixed rate and equal monthly payments. It does not fit interest-only periods, balloon payments or loans whose payment changes with income.
Does the table stay on my device?
Yes. The schedule is calculated in your browser. The download is created on your device and nothing you enter is sent to us.
Sources
Figures and text last checked on Tuesday, November 10, 2026.