This semicircle reference table shows the area for a range of radius values. Every figure is computed with the same engine that powers our Semicircle Calculator, so the numbers are exact.
| Radius | Area | Perimeter |
|---|---|---|
| 1.5 units | 3.5343 | 7.7124 |
| 3 units | 14.1372 | 15.4248 |
| 4.5 units | 31.8086 | 23.1372 |
| 6 units | 56.5487 | 30.8496 |
| 9 units | 127.2345 | 46.2743 |
| 12 units | 226.1947 | 61.6991 |
| 18 units | 508.9380 | 92.5487 |
| 30 units | 1,413.7167 | 154.2478 |
| 42 units | 2,770.8847 | 215.9469 |
| 60 units | 5,654.8668 | 308.4956 |
How to use this table
Find the row closest to your radius 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 Semicircle Calculator for a precise answer.
Need a value that is not in the table? — the Semicircle Calculator does it instantly, for free, with the formula and a worked example built in.
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