Amortization Calculator

An amortization schedule is a complete table of periodic loan payments showing the amount of principal and interest that comprise each payment until the loan is paid off. While your total payment remains the same, the ratio of principal to interest changes over time.

This amortization calculator allows you to model mortgages, auto loans, personal loans, and business loans. It provides three distinct modes: standard schedule generation, term-based calculation in months, and an advanced mode to see how extra monthly payments can drastically reduce your total interest and payoff time.

Switch payment frequency from monthly to biweekly to see how making 26 half-payments per year - the equivalent of 13 full monthly payments - can shave years off a 30-year mortgage and save a substantial amount in interest.

Suppose you borrow £250,000 over 25 years at 5% interest. The monthly payment is about £1,462 before any fees or insurance. In the first month, more than £1,040 of that payment is interest and only about £420 reduces the loan balance.

Later in the schedule, the balance is lower, so the interest portion shrinks and more of each payment goes toward principal. That is why a loan can feel slow to move at the beginning even when every payment is made on time.

If you add £100 extra per month, that extra money goes directly against principal. The saving is not just the £100 itself; it also avoids future interest on the amount you paid down early.

The headline payment only tells you what leaves your account each month. The amortization schedule shows the full cost of borrowing, when your balance falls, and how much interest you are likely to pay if you keep the loan unchanged.

This is useful when comparing loan offers. A slightly lower rate can save a large amount over a long term, while a longer term can make the payment look affordable but increase total interest.