Amortization Calculator

An amortisation schedule shows how each loan payment is split between interest and principal, and how the balance falls over time. The total payment may look steady, but the interest portion is usually highest early in the loan when the balance is largest.

This amortization calculator can model fixed-rate loans using a loan amount, interest rate, term, and payment frequency. Use Standard for a term in years, By Months for a precise number of months, or Extra Pay to test an additional payment each period.

The calculator shows the regular payment, total interest, total paid, payoff time, number of payments, balance-over-time chart, yearly schedule, and an optional full payment schedule. It does not calculate APR from fees, mortgage escrow, taxes, insurance, or variable-rate changes.

Suppose you borrow GBP 250,000 over 25 years at 5% interest. The monthly payment is about GBP 1,462 before any fees or insurance. In the first month, more than GBP 1,040 of that payment is interest and only about GBP 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 GBP 100 extra per month, that extra money goes directly against principal. The saving is not just the GBP 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.

Extra payments reduce principal sooner, which can reduce future interest and shorten the payoff time. The effect is easiest to see in the Extra Pay tab because the calculator compares the schedule with and without the added amount.

Changing payment frequency also changes the schedule. Monthly, biweekly, and weekly options create different numbers of payments per year, so compare them only when the payment pattern matches how the loan would actually be serviced.

The schedule shows how each payment is split between principal and interest as the balance falls.

Early payments often contain more interest because the outstanding balance is still high.

Extra payments reduce principal sooner, which can reduce future interest and shorten the payoff time.

The calculator does not include APR from fees, tax, insurance, escrow, variable-rate changes, or lender-specific rounding.

Using the schedule as an APR calculator when upfront fees are important.

Comparing payment frequencies without matching the real payment arrangement.

Assuming extra payments are allowed without checking early repayment limits or lender rules.

Start with the amortisation schedule here, then open apr when upfront fees matter, loan when you need max-loan or implied-rate modes, or loan payment for a quicker payment estimate.

Reuse the same loan amount, annual rate, term, and payment frequency across tools so comparisons stay fair.

If two tools disagree, check whether one includes fees, repayment timing, rounding, or a full payment schedule that the other omits.

Rerun the schedule when the loan amount, rate, term, payment frequency, or extra payment changes.

Review again before making extra payments so you can compare interest saved with any early repayment charge.

Keep a copy of the assumptions because real lender statements may use exact payment dates, daily interest, or rounding rules.