Normal Distribution Calculator
Calculate probabilities and percentiles for normal distribution with custom mean and standard deviation
About this calculator
The Normal Distribution Calculator helps you find probabilities and percentiles for any normal distribution by customizing the mean and standard deviation parameters. This powerful statistical tool is essential for researchers, students, and professionals who need to analyze data following a bell curve pattern. Whether you're calculating z-scores, finding areas under the curve, or determining specific percentile values, this calculator streamlines complex statistical computations and eliminates manual calculations.
How to use
Enter your desired mean and standard deviation values to define your normal distribution. Input either a specific value to find its probability or percentile, or enter a probability to find the corresponding value. Click calculate to get instant results including cumulative probabilities, percentiles, and z-scores for your custom normal distribution.
Frequently asked questions
What is a normal distribution?
A normal distribution is a bell-shaped probability distribution that's symmetric around the mean, where most values cluster near the center and fewer appear at the extremes.
How do I interpret the results?
The calculator shows cumulative probability (area under curve), percentile rank, and z-score, helping you understand where your value falls within the distribution.
Can I use this for standardized tests?
Yes, enter the test's mean and standard deviation to calculate percentiles, compare scores, and determine probability ranges for standardized test results.