Taxa Equivalente
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
conversão de taxa
About this calculator
The equivalent rate calculator converts an interest rate from one period to another using the formula i_eq = (1 + i)^m - 1, where i is the known rate and m is the number of periods in the new period. For example, to convert a monthly rate to an annual rate, m would be 12. This tool is useful for comparing investments or loans with different terms.
It works based on compound interest: the equivalent rate considers the effect of interest on interest. Unlike the proportional rate (which simply multiplies), the equivalent rate reflects the actual growth over time. Simply enter the original rate (as a percentage) and the number of periods (m) to get the converted rate.
Use this calculator when you need to compare interest rates of different terms, such as deciding between an investment yielding 1% per month and another yielding 12.68% per year. It is also useful for converting loan rates, such as from annual to monthly, or to calculate the effective rate for a shorter period from a longer rate.
Caution: the formula assumes compound interest. For simple interest, use the proportional rate. Make sure the entered rate is in decimal or percentage format correctly. Also, m must be a positive integer; for fractional periods, interpretation may vary.
Frequently asked questions
What is the difference between equivalent rate and proportional rate?
Equivalent rate uses compound interest (i_eq = (1+i)^m - 1), while proportional rate is linear (i_prop = i * m). For simple interest, use the proportional rate.
How do I convert an annual rate to a monthly rate using this calculator?
Enter the annual rate (e.g., 12% as 12) and m = 1/12 (or 0.08333). The result will be the monthly equivalent rate.
Can I use this calculator for inflation rates?
Yes, as long as inflation is compounded. But remember that inflation is volatile; the equivalent rate is a theoretical estimate.
What does a negative m mean?
m must be positive. If you want to convert to a shorter period, use a fractional m (e.g., 1/12 for monthly from annual).
Does the calculator work for discount rates?
Yes, but be careful: discount rates often use simple interest. Check if the context is compound interest.