Can it compute two-tailed probabilities?
Use the between mode with symmetric bounds (e.g., ±z) to obtain central or tail probabilities.
Step-by-step walkthrough
Normal Distribution Calculator Guide
Use this companion guide beside the interactive calculator to make sure you understand the “why” behind every click. Each section includes the classroom explanation, student-friendly language, and quick practice prompts.
Before you start
Collect the data points listed below and double-check their units. Keeping an organized “givens” list is one of the fastest ways to reduce math errors and impress exam graders.
- normal distribution
- z-score
- Gaussian
Detailed procedure
Step 1
Enter the mean μ and standard deviation σ.
Step 2
Provide one or two values depending on whether you want a single tail or a between probability.
Step 3
Read the z-score, PDF value, and probability.
Teaching & troubleshooting tips
What happens if σ = 0?
A zero or negative standard deviation is invalid for a normal distribution, so the calculator flags the input.