Financeiro
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Utilities
Interest
simple and compound
Simulate how a value grows over time with simple or compound interest. Enter the principal, rate, and number of periods to see the final amount and total interest — essential for understanding loans, investments, and financing.
How to use
- 1Choose between 'Simple interest' or 'Compound interest' depending on what you need to calculate.
- 2Enter the principal — the initial amount invested or borrowed.
- 3Type the interest rate per period, as a percentage (e.g., 2 for 2% per month).
- 4Enter the number of periods (months, years, etc.) the amount will earn or accrue interest.
- 5Select the currency — Real, Dollar, or Euro — so the result is formatted correctly.
Practical examples
$1,000 at 2% per month for 12 months (simple interest)
Interest earned is $240, for a total of $1,240 at the end of the period.
The same amount under compound interest
Interest earned rises to about $268 — the difference shows the effect of interest on interest over time.
Comparing loan offers
Use the calculator to simulate different rates and terms before deciding which offer is the better deal.
Frequently asked questions
What is the difference between simple and compound interest?
With simple interest, interest is always calculated on the initial amount. With compound interest, each period's interest is added to the principal, generating interest on interest.
Can I use this to calculate savings account returns?
Yes. Enter the deposited amount, the monthly rate, and the number of months to see the final balance.
How do I calculate the total cost of a loan?
Enter the loan amount, the monthly interest rate, and the term. The calculator shows the total paid and the interest amount.