Normal Distribution Calculator

Enter mean, standard deviation, and x values to compute area under the normal curve.

Modify the values and click the Calculate button to use this tool.

Normal Distribution Calculator

Find the probability that X falls between two values on a normal bell curve.

Formula

z = (x − μ) / σ  |  P = Φ(z₂) − Φ(z₁)

About the normal distribution

The bell curve models many natural phenomena. About 68% of values fall within 1σ of the mean, 95% within 2σ, and 99.7% within 3σ.