This octagon reference table shows the area for a range of side length values. Every figure is computed with the same engine that powers our Octagon Calculator, so the numbers are exact.
| Side length | Area | Perimeter |
|---|---|---|
| 1.3 units | 8.1600 | 10.4000 |
| 2.5 units | 30.1777 | 20.0000 |
| 3.8 units | 69.7225 | 30.4000 |
| 5 units | 120.7107 | 40.0000 |
| 7.5 units | 271.5990 | 60.0000 |
| 10 units | 482.8427 | 80.0000 |
| 15 units | 1,086.3961 | 120.0000 |
| 25 units | 3,017.7670 | 200.0000 |
| 35 units | 5,914.8232 | 280.0000 |
| 50 units | 12,071.0678 | 400.0000 |
How to use this table
Find the row closest to your side length and read across to the area. For a value between two rows, the real figure sits between them — or enter your exact numbers in the Octagon Calculator for a precise answer.
Need a value that is not in the table? — the Octagon Calculator does it instantly, for free, with the formula and a worked example built in.
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