You owe $1,568.00 on a credit card with a limit of $2,200.00 at an interest rate of 11.3%. You pay $300/month until it is paid off.

How many months does it take you to pay it off and how much is the total interest paid?

1 answer

To determine how long it will take to pay off the credit card balance and the total interest paid, we can use the following formula for monthly payments on a credit card:

  1. Calculate the monthly interest rate: \[ \text{Monthly interest rate} = \frac{\text{Annual interest rate}}{12} = \frac{11.3%}{12} = \frac{0.113}{12} \approx 0.00942 \]

  2. Use the balance, payment, and interest rate to set up an amortization equation. The remaining balance after each payment will be calculated as follows: \[ \text{New Balance} = \text{Old Balance} \times (1 + \text{Monthly interest rate}) - \text{Payment} \]

  3. Begin with the initial balance of $1,568.00 and subtract $300 monthly until it is paid off while adding interest.

Calculation:

Initial Balance = $1,568.00
Monthly Payment = $300.00
Monthly Interest Rate = 0.00942

Let's outline the monthly calculations to see how many months it will take to pay it off. We'll go through the iteration month-by-month:

  • Month 1: \[ \text{New Balance} = 1568 \times (1 + 0.00942) - 300 \approx 1568 \times 1.00942 - 300 \approx 1268.36 \]

  • Month 2: \[ \text{New Balance} = 1268.36 \times 1.00942 - 300 \approx 1268.36 \times 1.00942 - 300 \approx 973.96 \]

  • Month 3: \[ \text{New Balance} = 973.96 \times 1.00942 - 300 \approx 973.96 \times 1.00942 - 300 \approx 674.39 \]

  • Month 4: \[ \text{New Balance} = 674.39 \times 1.00942 - 300 \approx 674.39 \times 1.00942 - 300 \approx 376.51 \]

  • Month 5: \[ \text{New Balance} = 376.51 \times 1.00942 - 300 \approx 376.51 \times 1.00942 - 300 \approx 78.31 \]

  • Month 6: \[ \text{New Balance} = 78.31 \times 1.00942 - 300 \approx 78.31 \times 1.00942 - 300 \approx -220.4 \]

This shows that in Month 6, the remaining balance goes negative, indicating you fully pay off the debt during that payment.

Summary:

It takes 6 months to pay off the credit card debt.

Total Interest Paid Calculation:

To calculate total interest paid:

  1. Calculate the total amount paid: \[ \text{Total Paid} = \text{Monthly Payment} \times \text{Months Paid} = 300 \times 6 = 1,800 \]

  2. Subtract the original balance from the total paid to find total interest: \[ \text{Total Interest Paid} = \text{Total Paid} - \text{Initial Balance} = 1,800 - 1,568 = 232 \]

Results:

  • Number of months to pay off: 6 months
  • Total interest paid: $232.00