Borrowing options are compared by relating the principal, interest rate, time, compounding period, repayment amount, and fixed or transaction fees to the total cost of credit over a common term. The mathematics includes percent calculations and simple or periodically compounded interest when specified, emphasizing that a lower advertised rate may still produce a higher overall cost once fees and compounding are included. Detailed amortization schedules, variable rates, continuously compounded interest, and complex penalties are beyond this scope.
To compare borrowing options fairly, use the same principal and the same borrowing time for each option. Find:
A lower advertised interest rate does not always mean a lower total cost.
Example: You need to borrow 1{,}000$ for 1 year.
For simple interest, use
where:
For Option A:
The interest is 80$.
Add the fee to find the total cost of credit:
The total repayment is:
For interest compounded monthly, use
where:
For Option B, :
The interest is:
Now add the 70$ fee:
The total repayment is:
| Option | Interest | Fees | Total cost of credit | Total repayment |
|---|---|---|---|---|
| A | 80.00$ | 30.00$ | 110.00$ | 1{,}110.00$ |
| B | 61.68$ | 70.00$ | 131.68$ | 1{,}131.68$ |
Option B advertises the lower interest rate, but it has the higher fee. Therefore, Option A is cheaper overall by 21.68$:
Always compare the total cost of credit, not just the advertised interest rate.
Click a topic below to practice the foundational skills you'll need, learn the steps, or master this skill
Earned ?