Learn how to calculate the Simple Interest in Excel either for a single entry or a range or entries, between two dates, using this forumula.

To calculate per-diem interest, take the interest rate (be sure to express it as a decimal, so 10% becomes 0.10) and divide by 365 to determine the daily interest rate.

How to Find the Simple Interest Rate on a TI-83 Calculator. The TI-83 scientific calculator includes a finance-solving application that can do advanced calculations about the time value of money.

Learn more about interest on interest, or compound interest, including what it is, why it matters, and how to calculate compound interest accrued.