Can I paste a whole gradebook?
Yes. Switch to dataset mode, paste the values, and the calculator will compute the mean and σ before standardizing your target score.
Step-by-step walkthrough
Z-Score & Percentile 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.
- z-score
- percentile
- normal distribution
Detailed procedure
Step 1
Enter the raw score you want to benchmark.
Step 2
Choose whether you already know μ and σ or want the tool to estimate them from a dataset.
Step 3
Review the standardized z, percentile rank, right-tail probability, and deviation from the mean.
Teaching & troubleshooting tips
What if the standard deviation is zero?
A standard deviation of zero means every observation is identical, so z-scores and percentiles cannot be computed. Enter a more varied dataset or use a population σ.