Amortization Calculator guide
Amortization Calculator: Your Loan Repayment Schedule
Use our amortization calculator to see your monthly loan or mortgage payment and a full schedule of interest and capital, month by month or year by year.
By the AllCalculator editorial teamUpdated 16 October 20261 min read
An amortization (or amortisation) schedule shows exactly where each payment goes: how much is interest and how much pays off the loan. Our Amortization Calculator builds one for any mortgage or loan.
How to use the calculator (Amortization Calculator)
- Enter the loan amount.
- Enter the annual interest rate.
- Enter the term in years.
- Choose to see the schedule by year or by month.
How it works
The monthly payment stays the same, but its make-up changes:
- Interest for the month = balance × annual rate ÷ 12.
- The rest of the payment reduces the balance.
- Next month, interest is charged on the smaller balance, so more goes to capital.
Payment = P × r ÷ (1 − (1 + r)⁻ⁿ), where r is the monthly rate and n the number of payments.
A worked example
With the calculator's default settings, a £200,000 mortgage at 4.5% over 25 years:
- Monthly payment: £1,111.66
- In the first payment, £750 is interest (67%)
- You'll have repaid half the loan after about 16 years
- Total interest: £133,499
Frequently asked questions
Why do I repay so little at the start?
Because interest is charged on the whole balance at first. As the balance falls, the interest part shrinks.
How can I pay less interest?
Make overpayments, choose a shorter term or get a lower rate. Use our Paying Mortgage Off Early Calculator to see the effect.
Is this the same as my lender's figures?
Close, but lenders may calculate interest daily and round payments, so expect small differences.
Sources and further reading
Links open official and independent websites in a new tab.
This guide is general information to help you understand your options. It isn't financial, tax, legal or building advice and doesn't take your personal circumstances into account. Figures were checked when the guide was last updated and can change, so confirm anything important with GOV.UK, HMRC, a regulated adviser or a qualified tradesperson.