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Normal Distribution Calculator

The Distribution and Score calculators (inverse distribution calculator) compute cumulative probabilities (CDF), upper-tail probabilities (1 - CDF), probabilities between two values, probabilities outside two values, and probability density or mass (PDF/PMF) for many common statistical distributions:
  • Normal Distribution
  • Binomial Distribution
  • T Distribution
  • F Distribution
  • Chi Square Distribution
  • Poisson Distribution
  • Weibull Distribution
  • Exponential Distribution
  • Uniform Distribution Calculator
Select what you want to calculate:
  • P(X ≤ 𝑥) — the cumulative probability based on the score.
  • p(X ≥ 𝑥) — the upper-tail probability (1 − p) based on the score.
  • P(𝑥₁ ≤ X ≤ 𝑥₂) — the probability that X lies between 𝑥₁ and 𝑥₂.
  • P(X ≤ 𝑥₁), P(X ≥ 𝑥₂) — the probability that X lies outside the range 𝑥₁ to 𝑥₂.
  • P(X = 𝑥) — for discrete distributions, the probability that X equals 𝑥 (PMF).
  • PDF(X = 𝑥) — for continuous distributions, the value of the probability density function at 𝑥.
  • Score 𝑥 from P(X ≤ 𝑥) — the score corresponding to a given cumulative probability p.
  • Score 𝑥 from P(X ≥ 𝑥) — the score corresponding to a given upper-tail probability, 1 − p.
  • Scores 𝑥₁, 𝑥₂ — the left score from P(X ≤ 𝑥₁) and the right score from P(X ≥ 𝑥₂).
Less/Greater or Less-equal/Greater-equal
For discrete distributions, use the "≤ / ≥" switch button to switch between "Less" and "Less-equal", and "Greater" and "Greater-equal".
For continuous distributions, we hide the button because p(X < 𝑥) is equal to p(X ≤ 𝑥).