Weekly Interest Calculator

What is Weekly Interest?

Weekly interest is the amount of interest earned or charged on a principal amount over a period of one week. It's commonly used in short-term loans, savings accounts, and other financial products where interest is calculated and applied on a weekly basis.

The Weekly Interest Formula

The formula for calculating weekly interest is:

\[A = P(1 + \frac{r}{52})^n\]

Where:

• \(A\) = Final amount
• \(P\) = Principal amount
• \(r\) = Annual interest rate (in decimal form)
• \(n\) = Number of weeks

Step-by-Step Weekly Interest Calculation

1. Identify the principal amount (P), annual interest rate (r), and number of weeks (n).
2. Convert the annual interest rate to a weekly rate by dividing by 52.
3. Convert the weekly rate to decimal form (divide by 100).
4. Plug these values into the weekly interest formula.
5. Calculate the final amount (A).
6. Subtract the principal from the final amount to get the interest earned.

Example Calculation

Let's calculate the weekly interest for a principal of $1,000, an annual interest rate of 5.2%, over 52 weeks (1 year):

1. \(P = \$1,000\), \(r = 5.2\% = 0.052\), \(n = 52\) weeks
2. Weekly rate = \(0.052 \div 52 = 0.001\) or 0.1%
3. \(A = 1000(1 + 0.001)^{52} = \$1,053.20\)
4. Interest earned = \$1,053.20 - \$1,000 = \$53.20

Visual Representation

The green portion represents the principal ($1000), and the blue portion represents the weekly interest earned ($53.20) over one year.