Average Percentage Calculator
Last updated: November 14, 2026
Direct answer. Average percentage = (P1 + P2 + … + Pn) ÷ n. The percentages 80%, 90%, and 70% average to 80%.
Sometimes you need a single percent that represents several already-computed percentages: section scores on a practice SAT, weekly attendance figures, or category rates that your policy treats equally. This calculator takes the arithmetic mean. It is not a weighted average; that belongs on the weighted grade calculator.
Average Percentage Calculator
Average two or more percentages. This is a simple mean of the percentages themselves — it is not a weighted average of the underlying scores unless those percentages already share the same base.
Result
Key takeaways
- The average of percentages with equal weight is their arithmetic mean.
- 80, 90, and 70 average to 80.
- Do not use this tool when the items have different weights or different sample sizes.
- Each input is already a percent; the result is also a percent.
How to use this calculator
- Enter the first percentage.
- Add a row for each additional percentage.
- Read the average and the count of values included.
The formula
Every entered percent has weight 1. Blank rows are ignored. Units are percentage points of whatever those inputs already measured.
Worked examples
| Percentages | Count | Average |
|---|---|---|
| 80, 90, 70 | 3 | 80% |
| 100, 80 | 2 | 90% |
| 50 | 1 | 50% |
(80 + 90 + 70) ÷ 3 = 240 ÷ 3 = 80.
(100 + 80) ÷ 2 = 90.
When this is useful in the United States
A teacher who already converted three quizzes to percentages and wants a simple quiz average can list 80, 90, and 70 here, then move that 80% into a weighted course grade if quizzes are only one syllabus category.
A store comparing weekly conversion rates of 4%, 5%, and 6% can average those rates only if each week is treated as equal. If week sizes differ, a weighted average of the underlying counts is more honest.
Attendance figures that are already percents can be averaged this way only when each day or period is equally important.
Common mistakes
- Averaging 80%, 90%, and 70% and then treating the result as a weighted course grade when the exam is worth half the class.
- Entering raw scores such as 17 and 20 instead of the percentages 85 and 100.
- Averaging two rates that come from very different sample sizes and calling it the overall rate.
An average of percentages hides differences in the bases. A 90% on a 10-point quiz and a 70% on a 100-point exam should not be blended here if you care about total points; convert back to points, add, and recompute, or use weights. This page is deliberately narrow so that equal-weight cases stay easy to check. Equal-weight averages are honest only when each input deserves the same influence. A season batting average is not computed by averaging game percentages if the number of at-bats changes; the underlying counts should be pooled. The same warning applies to class attendance by week, store conversion rates by day, and quiz averages when the quizzes have different point totals. If you already know that every item is worth the same, this mean is the right tool and is easy to check by hand. If the items are not equal, stop here and use weights, or return to the raw counts and recompute a single overall percent. When a report asks for an “average percent,” ask whether the reader expects an equal-weight mean of already-computed percents or a pooled rate. A student with weekly attendance of 100%, 100%, and 50% on weeks of 5, 5, and 2 days does not have the same overall attendance as a simple mean of 83.3%; pooling the days is 12 of 12 on the first two weeks plus 1 of 2, which is 13 of 14, or about 92.9%. This calculator will still average 100, 100, and 50 if you type those percents, because that is what an equal-weight mean is. Use it when equal weight is the question you were asked. For course grades with listed weights, switch tools. For a single overall percent from raw totals, add the parts and the wholes yourself and then use the grade or ratio calculator. If you later add a new percent to the list, the average changes by a smaller amount as the count grows. That is expected of a simple mean. It is not a running weighted course grade and should not be pasted into a syllabus category that already has a listed weight.
Frequently asked questions
What is the average of 80%, 90%, and 70%?
It is 80%.
When should I use the weighted grade calculator instead?
When the syllabus or the data give the items different weights, or when you need to respect credits, points, or class sizes.
Does this convert fractions first?
No. Convert each item to a percentage first, then average the percentages.
Can I average a single value?
Yes. The average of one percentage is that percentage.