Amortization Schedule

Track your mortgage balance, payments, and interest over time

What is amortization?

Amortization is the process of paying off a loan through regular payments over time. Each payment is split between:

  • Interest – the cost of borrowing money, calculated on your remaining balance
  • Principal – the original amount you borrowed, which reduces your balance

In a standard mortgage, your monthly payment remains fixed, but the proportion going to interest vs principal changes over time.

Early in your mortgage, most of your payment goes toward interest. As you pay down the balance, more goes toward principal.

Example: £400,000 mortgage at 5% over 30 years
  • First payment: £1,667 interest + £480 principal
  • After 15 years: £1,100 interest + £1,047 principal
  • Final payment: £10 interest + £2,137 principal

When overpayments matter most

Making overpayments early in your mortgage term has the biggest impact because:

  • You reduce the principal sooner, meaning less interest accrues over the remaining term
  • Every £1 overpaid early can save £2-£3 in interest over the life of the loan

Overpayments later in the term save less interest because less time remains for interest to accumulate.

💡 Tip: If you can afford to overpay, do it in the first half of your mortgage term for maximum benefit.

Summary

Balance Chart

Interest vs Principal

Payment Schedule

Period Date Payment Interest Principal Paid Balance