Z-Score: Test Score 85, Mean 70, SD 10
A test score of 85 with a class mean of 70 and standard deviation of 10 gives a z-score of 1.5, meaning the score is 1.5 standard deviations above average.
How to use this tool
- Enter data point (x), mean (μ) and standard deviation (σ) in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your z-score and the full breakdown beneath it.
Calculate the z-score for a test score of 85 when the class average is 70 and the standard deviation is 10.
Frequently asked questions
- What does a z-score mean?
- A z-score of +1 means the value is 1 standard deviation above the mean; −2 means 2 standard deviations below. Z-scores allow comparison across different scales and distributions.