主な信頼区間に対する信頼度
| 信頼区間 | 信頼度 | 危険率 | 危険率（片側） |
| 0.674490σ | 50% | 50% | 75% |
| 1σ | 68.268949% | 31.731051% | 84.1344745% |
| 1.644854σ | 90% | 10% | 95% |
| 1.959964σ | 95% | 5% | 97.5% |
| 2σ | 95.449974% | 4.550026% | 97.724987% |
| 2.575829σ | 99% | 1% | 99.5% |
| 3σ | 99.73002% | 0.26998% | 99.86501% |
| 3.290527σ | 99.9% | 0.1% | 99.95% |
| 3.890592σ | 99.99% | 0.01% | 99.995% |
| 4σ | 99.993666% | 0.006334% | 99.996833% |
| 4.417173σ | 99.999% | 0.001% | 99.9995% |
| 4.891638σ | 99.9999% | 0.0001% | 99.99995% |
| 5σ | 99.999943% | 0.000057% | 99.9999715% |
| 6σ | 99.999999803% | 0.000000197% | 99.9999999015% |