The credit card interest calculator

A Piggybanker service

Credit Card Interest Calculator

Total amount owing on your credit or store card: £ more info
The interest rate (APR) of your credit card: % more info
How much you pay every month: £ more info

What is this?

This is a credit card interest calculator that will tell you how much interest you are paying with your current credit card and how long it will take to pay off the debt in full.


The tool also shows how much money, if any, you can save by transferring a balance from your store or credit card to a new one. The savings will come from the lower interest charges offered by a balance transfer card.

Does it cost anything?

No it's completely free for now.

What is Piggybanker?

Piggybanker is a price comparison website, but unlike other comparison websites Piggybanker presents a personalised comparison to take the guessing out of comparing credit cards.

How does the calculator work?

By entering the information above we can calculate whether a balance transfer will save you money. It includes the 'balance transfer fee' for each credit card. If it won't save you money we'll tell you so.

How can a balance transfer save me money?

By transferring a balance from a store or credit card to a balance transfer card, you are able to repay the debt on those cards at a much better rate (lower interest charge).

Why should I transfer my credit card balance?

Having large amounts of credit card debt costs you more of money the longer you hang take to pay it off. Paying small amounts off your balance each month might be more comfortable for you, but the credit card companies actually prefer that you only make the minimum payments because it makes them more money.


The calculator shows you what the cost of your borrowing will be in the long term. While the interest charges might be low in the short term, the total interest might shock you when you see it over a period of 12 or 24 months. Using the calculator, you can see what the quickest way of paying your debt is.


For example, if you have a debt of £3000 on a credit card with 17.9% APR and you make the monthly payment of £75, it will take you 59 months to pay off your credit card. In the meantime, you will have to pay £1355.15 in interest charges!


However, if you switch to the balance transfer card at the top of our comparison table, you will only have to pay £642.69 in interest over the same number of months, with the same monthly payments. That is a massive saving of £712.46!

I'm impressed / intrigued / amused / bewildered - how can I find out more?

The main piggybanker site is here. And we have an even niftier Facebook app (check out the savings calculator).