Examples of astigmatism power (′Pa) calculated for various “by the rule” axis values of J astigmatism from 1.00 to 5.00 D
| Dioptres | 90° | 80° | 70° | 60° | 50° | 45° | 40° | 30° | 20° | 10° | 0° |
| 1.00 | 0.50 | 0.42 | 0.36 | 0.32 | 0.30 | 0.29 | 0.30 | 0.32 | 0.36 | 0.42 | 0.50 |
| 2.00 | 1.00 | 0.84 | 0.72 | 0.63 | 0.59 | 0.59 | 0.59 | 0.63 | 0.72 | 0.84 | 1.00 |
| 3.00 | 1.50 | 1.26 | 1.08 | 0.95 | 0.89 | 0.88 | 0.89 | 0.95 | 1.08 | 1.26 | 1.50 |
| 4.00 | 2.00 | 1.68 | 1.44 | 1.27 | 1.18 | 1.17 | 1.18 | 1.27 | 1.44 | 1.68 | 2.00 |
| 5.00 | 2.50 | 2.10 | 1.80 | 1.58 | 1.48 | 1.46 | 1.48 | 1.58 | 1.80 | 2.10 | 2.50 |