Calculadora de Porcentagem Média
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
média = (p₁·n₁ + p₂·n₂) / (n₁ + n₂)
About this calculator
The Average Percentage Calculator computes the weighted average of percentages when groups have different sizes. For example, if a class has 20 students with an 80% pass rate and another has 30 students with a 90% pass rate, the simple average would be 85%, but the weighted average accounts for the larger second class, yielding a different result. The formula is: average = (p₁ × n₁ + p₂ × n₂) / (n₁ + n₂), where p is the percentage and n is the group size.
This calculator is useful for scenarios such as calculating the overall pass rate across multiple classes, the average productivity of teams with different employee counts, or the conversion rate of campaigns with varying lead volumes. It avoids the common mistake of simply summing percentages and dividing by the number of groups, which is only valid when all groups are the same size.
To use the tool, enter the percentages and their respective weights (group sizes) into the provided fields. The result is displayed as a percentage. Ensure that percentages are in decimal or percent format (e.g., 80 for 80%) and that weights are positive numbers. The calculator supports up to 5 groups but can be adapted for more.
Cautions: Make sure the weights correspond to the number of elements in each group, not another type of weight. Also, verify that percentages are in the same unit (all in % or all in decimal). Remember that the weighted average is influenced by the weights, so larger groups have more impact on the final result.
Frequently asked questions
What is the difference between simple average and weighted average of percentages?
The simple average treats all groups equally, summing percentages and dividing by the number of groups. The weighted average accounts for group size, giving more weight to larger groups. The weighted average is more accurate when groups have different sizes.
Can I use this calculator for school grade averages?
Yes, as long as the grades are percentages (e.g., 80% on a test) and you have the number of students or the weight of each test. For example, to calculate the overall average of two classes with different student counts.
What if I have more than 5 groups?
The current calculator supports up to 5 groups. For more groups, you can calculate in parts: combine some groups first and then use the result as a new group, or use a spreadsheet.
Do I need to convert percentages to decimals before using?
No, you can enter percentages as numbers between 0 and 100 (e.g., 80 for 80%). The calculator handles conversion internally. Just ensure all values are in the same format.
Can the result be greater than 100%?
Yes, if any percentage exceeds 100% (e.g., percentage growth), the weighted average can exceed 100%. The calculator does not limit the result, so verify that your data makes sense.