Add the three percentages and divide the total by three. For 70%, 85% and 90%, the mean is 81.67%.
Average Percentage Calculator
Enter your values below to get the result first, then scroll for the full explanation and guidance.
Average percentage
81.67%Arithmetic mean of three percentages
Average percentage: 81.67% (Arithmetic mean of three percentages)
Add the three percentages and divide by three. This treats each percentage equally; use a weighted calculation when the underlying group sizes differ.
Average percentage breakdown
Add the three percentages and divide by three. This treats each percentage equally; use a weighted calculation when the underlying group sizes differ.
Result snapshot
A quick visual read of the values behind this result.
Sum of percentages245%
Percentages counted3
Calculation245% / 3
Recommended next checks
- →Check that all three percentages refer to comparable measures.
- →Use a weighted average when the percentages represent groups of different sizes.
- Sum of percentages
- 245%
- Percentages counted
- 3
- Calculation
- 245% / 3
Try different values to compare results.
Enter three comparable percentages to calculate their simple arithmetic mean. The calculator adds the percentages and divides by three; it does not calculate an aggregate rate from groups of different sizes.
Average percentage
81.67%Arithmetic mean of three percentages
Average percentage: 81.67% (Arithmetic mean of three percentages)
Add the three percentages and divide by three. This treats each percentage equally; use a weighted calculation when the underlying group sizes differ.
Average percentage breakdown
Add the three percentages and divide by three. This treats each percentage equally; use a weighted calculation when the underlying group sizes differ.
Result snapshot
A quick visual read of the values behind this result.
Sum of percentages245%
Percentages counted3
Calculation245% / 3
Recommended next checks
- →Check that all three percentages refer to comparable measures.
- →Use a weighted average when the percentages represent groups of different sizes.
- Sum of percentages
- 245%
- Percentages counted
- 3
- Calculation
- 245% / 3
Try different values to compare results.
Table of Contents
Table of Contents
About Average Percentage Calculator
Average Percentage Calculator helps you work through the main numbers for this topic quickly with a simple input flow and an instant result.
Use the calculator result as a practical starting point, then review the explanation and assumptions on the page if you want more context.
Average percentage formula
Average percentage = (first percentage + second percentage + third percentage) / 3. Do not multiply by 100 again when the inputs are already percentages.
For example, (70% + 85% + 90%) / 3 = 81.67% after rounding to two decimal places.
When to use a weighted average
A simple mean gives each input equal weight. If each percentage comes from a group with a different number of observations, combine the underlying counts or use a weighted average instead.
Formula explained
Average percentage formula
This calculator gives three comparable percentages equal weight. It does not combine groups with different numbers of observations.
Formula
Average = (percentage 1 + percentage 2 + percentage 3) / 3
How the result is built
1Enter three percentages between 0% and 100%.
2Add the three percentages and divide by three.
3Use underlying counts or a weighted average if group sizes differ.
Example
Example: 70%, 85% and 90% average to 81.67%.
Assumptions
- Arithmetic mean = (first percentage + second percentage + third percentage) / 3.
- Each percentage has equal weight; use a weighted average if the group sizes differ.
Source basis
- Standard arithmetic mean
FAQ
Common questions
No. The entered values are already percentages, so their arithmetic mean is also a percentage.
When the percentages describe groups of different sizes. In that case, use the underlying counts or a weighted average.
Trust and notes
Assumptions and important notes
This calculator is designed to give a fast estimate using the method shown on the page. Results are most useful when your inputs are accurate and the tool matches your situation.
Use the result as guidance rather than a final diagnosis or professional decision. If the result could affect health, legal, financial, or compliance decisions, verify it with a qualified source where appropriate.
- Arithmetic mean = (first percentage + second percentage + third percentage) / 3.
- Each percentage has equal weight; use a weighted average if the group sizes differ.
Method
Arithmetic mean of percentages
Last reviewed
October 12, 2026