Normal Distribution Calculator

Use a mean and standard deviation to find left-tail, right-tail, between-range probabilities, or reverse-solve a percentile.

Mean (μ)

Standard deviation (σ)

Calculation

—Result

—Z-score

—Left-tail probability

—Right-tail probability

—Normal probabilities use the browser-side normal CDF.

How to use this Normal Distribution Calculator

Calculate normal-distribution probabilities, percentiles, and raw scores. Enter your values above and the result is calculated directly in your browser. No account is required.

Fast answer, clear inputs

This tool is built around one job: give the answer quickly without forcing a signup or hiding the result. Related tools are linked nearby when the next calculation or conversion is useful.