Credit Card Interest Rate Calculator for Calculating Weighted Average APR

Credit Card Interest Rate Calculator Sign

This calculator will calculate the weighted average APR for all of your credit cards that have a current balance.

Unlike most credit card interest calculators, this calculator will calculate the current finance charge for each card, and then compute the credit card average APR using a weighted formula.

Finally, the results include a button to create a printer-friendly report, as well as a 60-month minimum payment interest cost schedule.

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Also on this page:

Credit Card Interest Rate Calculator

Calculate weighted average interest rate on all credit card balances combined.

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Selected Data Record:

A Data Record is a set of calculator entries that are stored in your web browser's Local Storage. If a Data Record is currently selected in the "Data" tab, this line will list the name you gave to that data record. If no data record is selected, or you have no entries stored for this calculator, the line will display "None".

DataData recordData recordSelected data record: None
Enter Credit Cards

Enter Credit Cards:

To add a credit card, enter the name, balance, and interest rate. When you're satisfied with the entries, tap the + button (may also appear as "Add" or "Add Card" depending on the width of your device).

To edit a credit card in the list, tap the radio button in the Edit column. This will load the card into the form for editing. When you're satisfied with the changes you've made, tap the S button (may also appear as "Save" or "Save Changes" depending on the width of your device).

To delete a credit card from the list, tap the radio button in the Edit column. This will load the card into the form for deleting. Tap the button (may also appear as "Delete" depending on the width of your device).

To clear the form to create a new credit card entry, tap the C button (may also appear as "Clr" or "Clear" depending on the width of your device).

To add a credit card to your credit card interest rate analysis, click the Add Credit Card Row button. Then complete the row of entries for the card you are adding.

To remove a credit card from your credit card interest rate analysis, click the X button in the left-hand column of the row you wish to remove.

Important! The entered credit cards are saved in your device's random memory (temporary storage), which means that if you surf to another calculator or close this browser window you will need to re-enter your cards.

Cost percentage:

The number in this column represents the percentage of total interest charges for the month that each card cost represents.

Tab out of each changed entry field to recalculate the percentage.

X
Card
Name

Credit card name:

Enter the name of the credit card as you want it to appear on the printed report. Note that if the card statement lists more than one interest rate (1 for purchases, 1 for cash advances, etc.), I suggest you enter the balances as separate cards (Visa purchases, Visa cash, etc.).


Statement
Balance ($)

Statement balance:

Enter the statement balance of the credit card, without any dollar sign or commas.


Interest
Rate (%)

Annual interest rate:

Enter the annual interest rate of the credit card. Enter as a percentage without the percent sign (for .06 or 6%, enter 6). If this credit card has more than one interest rate (1 for purchases, 1 for cash advances, etc.), enter the individual rate balances as separate cards (Visa purchase, Visa cash, etc.).


Interest
Cost

Current month interest cost:

Based on your statement balance and interest rate, this is how much interest you will be charged on the balance for the current month.

Tab out of each changed entry field to recalculate the interest cost.


% of
Cost

Percent of total cost:

Based on your balance and interest rate, this column will show the percentage of the total current month interest that each card represents.

Totals: 
Card name:Card name:Credit card name:Credit card name:

Credit card name:

Enter the name of the credit card as you want it to appear on the printed report. Note that if the card statement lists more than one interest rate (1 for purchases, 1 for cash advances, etc.), I suggest you enter the balances as separate cards (Visa purchases, Visa cash, etc.).

Balance:Balance:Statement balance:Statement balance:

Statement balance:

Enter the statement balance of the credit card, without any dollar sign or commas.

$
Rate:Interest rate:Annual interest rate:Annual interest rate:

Annual interest rate:

Enter the annual interest rate of the credit card. Enter as a percentage without the percent sign (for .06 or 6%, enter 6). If this credit card has more than one interest rate (1 for purchases, 1 for cash advances, etc.), enter the individual rate balances as separate cards (Visa purchase, Visa cash, etc.).

%
Interest:Interest cost:Current month interest cost:Current month interest cost:

Current month interest cost:

Based on your statement balance and interest rate, this is how much interest you will be charged on the balance for the current month.

Avg APR:Average APR:Credit card average APR:Credit card weighted average APR:

Credit card average APR:

This is the weighted average APR of all of your entered credit cards.

Cost / 1%:Cost per 1%:Monthly cost per 1%:Monthly cost per 1% of average APR:

Monthly cost per 1% of average APR:

This is how much each 1% of the weighted average APR is costing you. In other words, for each 1% you are able to lower your average APR, this is how much you will save each month if the balances stay the same.

If you would like to save the current entries to the secure online database, tap or click on the Data tab, select "New Data Record", give the data record a name, then tap or click the Save button. To save changes to previously saved entries, simply tap the Save button. Please select and "Clear" any data records you no longer need.

Help and Tools

Learn

What weighted average is and why it's important.

What is a Weighted Average?

A weighted average takes into consideration how much each card's finance charges represents of the whole -- giving more weight to the interest rates of cards with higher balances.

Suppose you have two cards. The first card has a balance of $5,000 with an annual percentage rate of 18%. The second card has a balance of $1,000 with an annual rate of 12%.

If you use the common method of calculating the average APR (known as the "mean" average), you would add the two rates together and divide by two, giving you an average APR of 15% (18% + 12% = 30% ÷ 2 = 15%).

However, if you calculate the actual finance charge for the two cards, you will see that the numbers don't add up.

CardBalanceAPRCurrent
Month
Finance
Charge
Card #1$5,00018%$75.00
Card #2$1,00012%$10.00
Totals$6,000?$85.00

If we divide 15% by 12 to get the monthly rate of .0125 (.15 ÷ 12) and multiply the balance by that result, the total finance charge for the two cards would be $75. Obviously, that is not correct.

In order to get the actual average rate, we need to work backwards. First we take the $85 and divide that by the total balance to get a monthly rate of .0142 ($85 ÷ $6,000 = .0142 rounded). Multiplying .0142 by 100 and then by 12 gives us the actual average annual rate of 17% (.0142 * 100 = 1.42 * 12 = 17% rounded).

The reason the actual average is higher than 15% is that the card with the higher balance has more influence (weight) on the average than the card with the lower balance. Hence the term "Weighted Average."

Why is Knowing Average APR Important?

Now that you understand what "weighted average" means, you should now have a clear idea of how to prioritize your efforts to get your interest rates lowered.

Since it's the weighted average that determines how much interest you will pay on all of your cards, you will want to focus all of your efforts on lowering the rates of your highest rate, highest balance cards, because they carry the most weight.

Adjust Calculator Width:

Move the slider to left and right to adjust the calculator width. Note that the Help and Tools panel will be hidden when the calculator is too wide to fit both on the screen. Moving the slider to the left will bring the instructions and tools panel back into view.

Also note that some calculators will reformat to accommodate the screen size as you make the calculator wider or narrower. If the calculator is narrow, columns of entry rows will be converted to a vertical entry form, whereas a wider calculator will display columns of entry rows, and the entry fields will be smaller in size ... since they will not need to be "thumb friendly".

Show/Hide Popup Keypads:

Select Show or Hide to show or hide the popup keypad icons located next to numeric entry fields. These are generally only needed for mobile devices that don't have decimal points in their numeric keypads. So if you are on a desktop, you may find the calculator to be more user-friendly and less cluttered without them.

Stick/Unstick Tools:

Select Stick or Unstick to stick or unstick the help and tools panel. Selecting "Stick" will keep the panel in view while scrolling the calculator vertically. If you find that annoying, select "Unstick" to keep the panel in a stationary position.

If the tools panel becomes "Unstuck" on its own, try clicking "Unstick" and then "Stick" to re-stick the panel.