Calculadora de Porcentagem de Porcentagem
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
resultado% = (A × B) / 100
About this calculator
The percentage of percentage calculator solves a specific type of calculation: finding the value of a percentage applied to another percentage. For example, what is 20% of 50%? The result is expressed as a percentage of the original total. The formula is simple: multiply the two percentages (A and B) and divide by 100. In the example, (20 × 50) / 100 = 10%, meaning 20% of 50% equals 10% of the base value. This tool is useful when you need to combine percentage rates, such as cascading discounts or tax on tax.
How to use: enter the first percentage (A) and the second percentage (B). The calculator returns the result as a percentage. It is important to understand that the result is a percentage of the original value, not an absolute value. For example, if a product costs R$ 100 and receives a 20% discount followed by a 50% discount, the total discount is not 70%, but rather (20% of 50%) which is 10% of the original value? Actually, successive discounts are not calculated this way; this calculator is for situations where a percentage rate is applied to another, such as compound interest or tax on tax.
When to use: in finance, when calculating compound interest rates where one rate applies to another; in statistics, to determine proportions of proportions; in progressive discounts, when a discount is applied to an already discounted value (discount on discount). Caution: do not confuse with adding percentages. For example, 20% of 50% is not 70%, but 10%. Always verify if the context requires multiplication or addition of percentages.
Common pitfalls: remember that the result is a percentage, not a monetary value. To convert to an absolute value, multiply by the base value. Also, the order of factors does not change the result (A% of B% equals B% of A%). Avoid using this calculator for simple successive discounts, where the second discount applies to the already discounted value (in that case, the calculation is different: final value = original value × (1 - rate1) × (1 - rate2)).
Frequently asked questions
What is the difference between percentage of percentage and sum of percentages?
Percentage of percentage is multiplication: A% of B% = (A×B)/100. Sum of percentages is addition: A% + B% = (A+B)%. They are different operations used in different contexts.
Can I use this calculator for successive discounts?
Not directly. Successive discounts (e.g., 20% off then 10% off the discounted price) are calculated by multiplying factors (1 - rate). This calculator is for compound rates, not sequential discounts.
Is the result an absolute value or a percentage?
The result is a percentage. To get the absolute value, multiply that percentage by the base value (e.g., 10% of $200 = $20).
Does the order of percentages change the result?
No. 20% of 50% equals 50% of 20%, both result in 10%. Multiplication is commutative.
How to calculate 20% of 50% of a number?
First, calculate the compound percentage: (20×50)/100 = 10%. Then, multiply 10% by the number. Example: 10% of 200 = 20.