๐Normal Distribution Calculator
Enter the mean and standard deviation, choose a probability type, and get the area under the curve.
Free Normal Distribution Calculator
This normal distribution calculator finds the probability โ the area under the bell curve โ below a value, above a value, or between two values, given the distribution's mean and standard deviation. It works by converting your value(s) to z-scores using z = (x โ ฮผ) / ฯ, then computing the cumulative probability from the standard normal distribution.
Normal distributions show up everywhere in statistics: test scores, heights, measurement errors, and countless natural phenomena approximate this bell-shaped curve. Whether you're checking what percentage of a population falls in a range, or finding a percentile, this tool gives you the answer instantly along with the z-scores used.
Free, runs entirely in your browser, no sign-up required.