Calculate regular polygon sum of interior angles.
GeometryOpen
Regular Polygon Interior Angle Calculator
Quick answer
If number of sides are 6, the interior angle is 120 °.
Enter your values
Interior angle
120°
The angle worked out from the values you entered, in degrees.
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See how the result changes
Each table re-runs this calculator with one value changed and everything else left as it is.
Interior angle by number of sides
If number of sides goes from 6 to 9, interior angle changes from 120 ° to 140 ° (+17%).
| Number of sides | Interior angle |
|---|---|
| 3 | 60 ° |
| 6start | 120 ° |
| 9 | 140 ° |
| 12 | 150 ° |
MATH GUIDE
A quick guide to Regular Polygon Interior Angle
Use it to get an accurate interior angle in seconds — free, with no sign-up.
Instant results
See your interior angle the moment you enter your numbers.
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How to Use the Regular Polygon Interior Angle Calculator
1
Enter Number of sides
Provide your number of sides.
2
View Your Results
Get your interior angle instantly, calculated on our server.
What is Regular Polygon Interior Angle?
This math tool works out your interior angle instantly, so you don't have to do the math by hand.
“One quick calculation, so you always know your interior angle before you decide.”
What Affects Your Interior angle
Your interior angle depends on the values below.
Number of sides
Changing your number of sides changes your interior angle. Typically between 3 and 100.
Example Result
Here's what you can expect from a regular polygon interior angle calculation:
- Number of sides
- 6
- Interior angle
- 120 °
Frequently Asked Questions
- How does number of sides affect interior angle?
- If number of sides goes from 6 to 9, interior angle changes from 120 ° to 140 ° (+17%).
- How to calculate regular polygon interior angle?
- Fill in number of sides in the Regular Polygon Interior Angle Calculator above and your interior angle is calculated instantly. Change any value to see how the result responds.
- What does an example regular polygon interior angle calculation look like?
- If number of sides are 6, the interior angle is 120 °.
- Is this calculator free to use?
- Yes — every calculator on this site is completely free, with no sign-up or account required.
- How accurate is this calculator?
- It uses the standard formula and calculates on our server for every request, so results are precise for the values you enter.
- Is my data saved anywhere?
- No. Nothing you enter is stored or sent anywhere unless you choose to share a link with your values included.
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