How do you find the average of multiple percentages?

To find the simple average of multiple percentages, add all the percentage values together and divide by the count. For example, the average of 40%, 60%, and 80% is (40 + 60 + 80) / 3 = 60%. This works when every percentage represents an equal-sized group or observation. If the groups are different sizes, use a weighted average instead: multiply each percentage by its weight (such as the size of the group), sum those products, then divide by the total weight.

When should I use a weighted average percentage instead of a simple average?

Use a weighted average when the groups or samples behind each percentage are different sizes. For example, if Class A has 10 students with 70% passing and Class B has 30 students with 90% passing, the simple average (80%) is misleading because Class B is three times larger. The weighted average is (10 x 70 + 30 x 90) / (10 + 30) = (700 + 2,700) / 40 = 85%. Use simple averaging only when all groups are the same size or you are averaging independent rates with equal importance.

Can you average percentages that add up to more than 100%?

Yes. Percentages used in averaging are treated as ordinary numbers. They do not have to sum to 100% and can be above 100% (for example, growth rates or markup percentages). The arithmetic mean formula applies regardless: sum the values and divide by the count. For example, if three products have markups of 50%, 120%, and 200%, the average markup is (50 + 120 + 200) / 3 = 123.3%. The restriction that percentages must sum to 100% applies only when percentages represent shares of a whole (like a pie chart), not when they are independent measurements.

Average Percentage Calculator

This calculator finds the average of a set of percentage values, using either a simple arithmetic mean or a weighted average when the percentages come from groups of different sizes. Averaging percentages incorrectly is a common mistake: a simple average treats every percentage as equally important, which can badly distort the result if, for example, one group has ten people and another has a thousand. To use it, choose how many percentage values you want to average, from two up to ten, then enter each one in the table provided. If you select the weighted average option, an extra column appears so you can enter a weight for each value, such as the number of students, respondents, or units behind that percentage. You can also set how many decimal places to show in the result, from whole numbers up to three decimal places. The calculator instantly returns your average percentage, the number of valid entries included, and either the sum of the percentages for a simple average or the weighted sum of percentage times weight for a weighted average, along with a full step-by-step breakdown of the arithmetic so you can check the working. Use this tool for averaging test scores, pass rates, survey results, growth rates, or any other set of percentages, and switch to weighted averaging whenever the groups behind your figures differ meaningfully in size.

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Standard formula Arithmetic mean and weighted mean of percentage values.

1. Percentage Values

Number of values

#	Percentage (%)	Weight

Please enter at least two valid percentage values.

2. Options

Average type

Decimal places in result

When to use weighted average: Use weighting when the groups or samples behind each percentage are different sizes. For example, if 10 students scored 70% and 30 students scored 90%, the weighted average (85%) is more accurate than the simple average (80%).

Result

Average Percentage
-
Simple average

Values Included

Valid entries

Sum of Percentages

Total before dividing

Step-by-Step Working

Enter your values above to see the working.

How the Average Percentage Calculator Works

The calculator computes the arithmetic mean of the percentage values you enter. This is the standard method for averaging a set of numbers.

Simple Average Formula

When all values are equally important (for example, five separate test scores with no difference in exam weight), the formula is:

Average = (P1 + P2 + ... + Pn) / n

Where P1 through Pn are the individual percentage values and n is the count of values.

Worked Example (matches calculator defaults)

Default values: 40%, 60%, 80% (3 values, simple average).

#	Value
1	40%
2	60%
3	80%

Sum = 40 + 60 + 80 = 180

Count = 3

Average = 180 / 3 = 60.00%

Weighted Average Formula

When each percentage applies to a different-sized group, you weight each value by the size of its group:

Weighted average = (P1 x W1 + P2 x W2 + ... + Pn x Wn) / (W1 + W2 + ... + Wn)

For example: 70% from a class of 10 and 90% from a class of 30 gives (70 x 10 + 90 x 30) / (10 + 30) = (700 + 2,700) / 40 = 85.00%.

Common Uses

Averaging exam or test scores across subjects
Finding the average pass rate across multiple classes or cohorts
Combining survey response rates from different groups
Averaging discount or growth rates over time periods
Combining accuracy rates from multiple models or trials

A Note on When Simple Averaging is Misleading

If each percentage applies to a different number of items, a simple average can give the wrong answer. Suppose a shop sold 1 item at a 50% margin and 999 items at a 10% margin. The simple average margin is (50 + 10) / 2 = 30%, which is far above the true blended margin of (1 x 50 + 999 x 10) / 1000 = 10.04%. Always use weighted averaging when group sizes differ significantly.

Related Calculators

Maths and Stats Calculators: full list of maths tools on this site.
Average Calculator: mean, median, and mode for any set of numbers.
Weighted Average Calculator: general-purpose weighted mean tool.
Percentage Calculator: calculate percentages, percentage change, and more.
Percentage Change Calculator: find the percentage increase or decrease between two values.

Method: Arithmetic mean (simple average) and weighted arithmetic mean. Both are standard statistical operations. No external data sources are required.

This calculator performs standard arithmetic averaging of the percentage values you enter. It does not validate whether those percentages are statistically comparable. If your percentages come from different populations or measurement methods, interpret the average with care.