Average Percentage Calculator
Find the average of several percentages, give each rate a different weight, or combine results from groups of different sizes.
- Rows
- 2
- Sum of percentages
- 140%
- Unweighted average
- 70%
Each row has equal weight.
Show working
Average = sum of percentages / number of rows Row 1: 50% with weight 1 Row 2: 90% with weight 1 140 / 2 = 70%
How to average percentages
An average percentage describes several rates with one number. Which calculation is appropriate depends on what you want each rate to represent. Give every rate equal weight when each row should count equally. Use group sizes as weights when you want the overall rate across all observations.
Simple average = sum of percentages / number of percentages
For 60%, 75% and 90%, the sum is 225%. Dividing by three gives an average of 75%. This is the mean of those three rates; it does not automatically give the combined success rate if the groups have different sizes.
Weighted percentages and combined totals
For marketing campaigns, the conversion rate calculator combines traffic and conversion totals using consistent counting rules. It also compares campaign rates and solves traffic targets.
A small group and a large group do not contribute equally to an overall result. Multiply each percentage by its weight, add the products, then divide by the sum of the weights.
Weighted average = sum of (percentage x weight) / sum of weights
Suppose 5 of 10 people in one group and 90 of 100 people in another group completed a task. Their rates are 50% and 90%. The simple average is 70%, but the combined rate is 95 / 110 x 100 = 86.3636%. The larger group accounts for more observations.
| Group | Completed | Total | Rate |
|---|---|---|---|
| A | 5 | 10 | 50% |
| B | 90 | 100 | 90% |
| Combined | 95 | 110 | 86.3636% |
When exact counts are available, use them rather than rounded percentages. A displayed rate of 33.3% may be an approximation, and weighting that rounded value can introduce a small difference.
Choosing the right weights
Weights can be counts, proportions or relative importance. Weights of 2 and 3 produce the same average as weights of 20 and 30. They do not need to total 100, but each included weight must be positive.
For course assignments and final-exam targets, use the grade calculator. To find one group’s rate first, use percentage of total. Annual growth rates require a different interpretation: repeated changes compound, so an arithmetic average does not describe the full growth path. The CAGR calculator handles equivalent annual growth between starting and ending values.
Common questions
Can I average two percentages by adding them and dividing by two?
Yes, for an equally weighted mean of the two rates. For a combined population rate, this gives the correct answer only when the group sizes are equal, or the two rates happen to be equal.
Can a percentage average exceed 100%?
It can when the entries describe quantities such as growth or progress beyond a target. A success rate based on successes out of total observations is restricted to 0-100%. The combined-totals mode checks that successes do not exceed each total.
Why does my combined rate differ from my spreadsheet average?
A spreadsheet AVERAGE of percentage cells gives each cell equal weight. A combined rate divides total successes by total observations. Check the denominator behind each percentage before choosing the calculation.
Related calculators
Back to the Percent Calculator.