Math calculators

Average Percentage Calculator

Updated May 24, 2026 By Jehan Wadia
Simple Average of Percentages
Enter values separated by commas or new lines. The % sign is optional.
Please enter at least one valid percentage value.

Introduction

The Average Percentage Calculator helps you find the average of two or more percentages quickly and accurately. You can use it in two ways. Simple Average adds up all your percentages and divides by the total count. Weighted Average lets you assign a weight or sample size to each percentage, which is useful when some values matter more than others. For example, if one test is worth more points than another, a weighted average gives you a more accurate result. Just enter your values, click calculate, and get your answer instantly along with a full breakdown of the math.

How to Use Our Average Percentage Calculator

Enter your percentage values to quickly find the simple or weighted average. The calculator will show the average along with helpful stats like the minimum, maximum, median, range, and standard deviation.

Simple or Weighted Mode: Click the "Simple Average" tab if all your percentages count equally. Click the "Weighted Average" tab if some percentages matter more than others based on a weight or sample size. If you need to calculate a weighted average for non-percentage values, our Weighted Average Calculator can help.

Enter Percentages (Simple Mode): Type your percentage numbers into the text box, separated by commas or new lines. The % sign is optional. For example, you can type "85, 90.5, 72" or "85%, 90.5%, 72%".

Percentage (Weighted Mode): Enter each percentage value in the left input field of each row. For example, type "85" if the percentage is 85%.

Weight / Sample Size (Weighted Mode): Enter the weight or sample size for each percentage in the right input field. A higher number means that percentage counts more toward the final average.

Add Another Row: Click this button to add more percentage and weight pairs. You can add up to 25 rows.

Calculate Average: Click this button to see your results. The calculator will display the average percentage, a breakdown of the formula used, summary stats, and a bar chart of your values.

Clear: Click this button to erase all inputs and start over.

What Is an Average Percentage?

An average percentage is the middle value you get when you combine two or more percentages together. To find it, you add up all the percentages and divide by how many there are. For example, if you scored 80%, 90%, and 70% on three tests, the average percentage is (80 + 90 + 70) ÷ 3 = 80%. For general average calculations beyond percentages, you can also use our Average Calculator.

Simple Average vs. Weighted Average

A simple average treats every percentage equally. You just add them up and divide by the total count. This works well when each value matters the same amount, like averaging quiz scores that are all worth the same points. Our Mean Median Mode Calculator can also help you explore these central tendency measures in more detail.

A weighted average is different. It gives more importance to some percentages than others based on a weight or sample size. For example, if one class has 200 students with a 92% pass rate and another has 50 students with a 78% pass rate, the weighted average accounts for the fact that the larger class should count more. The formula is: multiply each percentage by its weight, add those results together, then divide by the total of all weights.

When to Use a Weighted Average

Use a weighted average when the groups behind each percentage are not the same size. Common examples include:

  • Combining pass rates from classes with different numbers of students
  • Averaging survey results from groups of different sizes
  • Calculating a final grade when assignments have different point values — our Grade Calculator and Weighted GPA Calculator are also great tools for this
  • Merging conversion rates from marketing campaigns with different traffic amounts

If you use a simple average in these cases, your result can be misleading because smaller groups get the same influence as larger ones.

How to Calculate Average Percentage by Hand

Simple average formula: Add all percentages together, then divide by the number of values.

Weighted average formula: Multiply each percentage by its weight. Add all those products together. Then divide by the sum of all weights.

This calculator does both methods for you instantly and also shows the minimum, maximum, median, range, and standard deviation of your values so you can understand the full picture. If you need to work with other percentage calculations, check out our Percentage Calculator, Percent Change Calculator, Percent Difference Calculator, or Percent Error Calculator.


Frequently asked questions

Can I enter negative percentages?

Yes. The calculator accepts negative numbers. Just type a minus sign before the number, like -5. This can be useful for things like negative growth rates or percentage losses.

Do I need to type the % sign?

No. The % sign is optional. You can type 85 or 85% and the calculator treats them the same way.

What happens if I enter percentages over 100?

The calculator will still work. Values above 100% are valid in many real-world cases, like a 150% increase in sales. The tool does not limit your input to a 0–100 range.

How many values can I enter in simple mode?

There is no strict limit in simple mode. You can type as many comma-separated or line-separated values as you need into the text box.

How many rows can I add in weighted mode?

You can add up to 25 rows in weighted mode. Click the "Add Another Row" button to create a new pair of percentage and weight fields.

Can I remove a row in weighted mode?

Yes. Click the red X button next to any row to remove it. You must keep at least two rows, so the remove button is disabled when only two rows remain.

What does the weight or sample size mean?

The weight tells the calculator how much each percentage should count. A percentage with a weight of 200 has twice the influence of one with a weight of 100. Common examples of weights include number of students, survey respondents, or total points on an assignment.

Can I use decimals for percentages and weights?

Yes. Both fields accept decimal numbers. For example, you can enter 85.75 as a percentage and 50.5 as a weight.

What is the standard deviation shown in the results?

Standard deviation measures how spread out your percentages are from the average. A small standard deviation means the values are close together. A large one means they are more spread apart.

Why is my weighted average different from my simple average?

A weighted average gives more importance to percentages with higher weights. If the percentages with larger weights are higher or lower than the others, the weighted average will shift toward those values. A simple average treats every percentage equally.

What does the Contribution column mean in the weighted detail table?

The Contribution column shows how much each percentage adds to the final weighted average. It is calculated by multiplying the percentage by its weight, then dividing by the total of all weights. All contributions added together equal the weighted average.

Does the calculator round the results?

Yes. All results are rounded to two decimal places. This gives you a precise answer that is still easy to read.

What does the red line on the bar chart mean?

The red dashed line on the chart shows the average percentage. It helps you quickly see which values are above or below the average.

Can I use this calculator for grades?

Yes. You can enter your test or assignment scores as percentages. Use simple mode if every assignment is worth the same. Use weighted mode if assignments have different point values, and enter the point value as the weight.

What happens if I leave a row blank in weighted mode?

The calculator skips any row that has a missing or invalid percentage or weight. Only rows with a valid number in both fields are included in the calculation.

Can I enter a weight of zero?

No. A weight of zero means that percentage has no influence, so the calculator ignores that row. Weights must be greater than zero to be counted.