Normal distribution percentile calculator
One-sided or two-sided probability (area under the standard normal curve) for a given t-value.
Probability, R(t)94.95 %
Method & references
- Standard normal distribution percentile — one-sided or two-sided probability for a given t-value.
The computation is a literal port of the original client-side JavaScript from /calculators/t1_2a.htm. Results are verified equal to the original by an automated golden-master test. No formula has been re-derived or “improved”.