How our credit card calculator works

There are two versions of our credit card calculator. One that works out how much users would save if they transferred a balance from one card to another, and one that works out the interest, charges and cashback over a chosen time period for a new card.

Our results show a typical Annual Percentage Rate (APR) for each credit card. A lender’s APR is used in conjunction with a system called risk based pricing. This means that they assess each individual’s circumstances and credit history before deciding what rate to offer the individual. However, if they quote a typical APR they have to give this to at least 66% of people that apply for it, so by law there is a reasonable chance an applicant will get the rate stated.

Compare 0% Purchase cards...

For the balance transfer version of the calculator we ask for the outstanding balance to be transferred and the existing card. We then compare the interest rate of that card against every card in the market that allows a balance to be transferred to it. We calculate how much will be saved over a period chosen by the user, using the interest rate of each card. The calculation takes into account any special offers such as introductory 0% periods, and any fees that are applied by lenders. The time period over which the savings are calculated can be changed.

The calculator takes the amount a user selects they will spend each month, and the amount that will be paid back, and calculates what the interest, charges and cashback will be over the time period selected. The calculation includes any offers from the cards, such as introductory 0% periods for purchases, and any fees that are applied.