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Loan Repayment Schedule
See exactly where every payment goes. Each row shows how much of your payment covers interest, how much pays down the loan, and what's still owed.
Loan details
Optional. Overpayments reduce the loan term and total interest.
Principal vs interest over time
Outstanding balance over the life of the loan.
| Year | Payment | Principal | Interest | Balance |
|---|
How loan amortization works
Amortisation is how a loan with a fixed monthly payment gets paid down over time. The payment itself stays the same, but the split between interest and principal shifts each month: early payments are mostly interest, later payments are mostly principal. The schedule shows that split month by month so you can see exactly where your money is going.
The mechanics
- Monthly interest = current balance × (annual rate ÷ 12)
- Monthly principal = monthly payment − monthly interest
- New balance = old balance − monthly principal
Repeat for every month until the balance hits zero. The fixed monthly payment is calculated up-front using the standard amortisation formula so the loan finishes exactly on the final scheduled payment.
Worked example
Scenario: £200,000 loan, 5% rate, 25-year term.
Monthly payment: £1,169
Month 1: Interest £833, Principal £336. Balance falls to £199,664.
Month 150 (halfway): Interest £541, Principal £628. Balance ~£129,000.
Month 300 (final): Interest £5, Principal £1,164. Balance £0.
Total interest over the life of the loan: ~£150,754 — three-quarters of the original capital.
Frequently asked questions
What is loan amortization?
Amortization is the process of paying off a loan in equal periodic instalments, where each payment covers part interest and part principal. Early on, most of the payment goes to interest; later, most goes to principal. By the final payment, the balance reaches zero.
Why is most of my early payment interest?
Interest is charged on the outstanding balance, which is highest at the start of the loan. As you chip away at the principal, the interest portion of each payment shrinks and the principal portion grows — until in the final years almost the whole payment goes to capital.
How are overpayments applied?
Overpayments reduce the principal directly, which means every future month's interest is calculated on a smaller balance. Even modest, regular overpayments can shave years off a 25-year loan and save tens of thousands in interest.
What's the difference between APR and interest rate?
The interest rate is what's charged on the loan balance. APR (Annual Percentage Rate) wraps the rate together with mandatory fees so you can compare loans on a like-for-like basis. The amortisation table here uses the pure interest rate.
Does this work for car loans and personal loans?
Yes — any standard amortising loan with a fixed rate and equal monthly payments works the same way mathematically, whether it's a 30-year mortgage, a 5-year car loan, or a 3-year personal loan. Just plug in the principal, rate, and term.
What happens if my rate is variable?
This calculator assumes a fixed rate for the full term. For variable or tracker loans, the schedule is accurate only until the rate changes; rerun it with the new rate when that happens.