Maths & numbers
Z-score calculator
Express a value in standard deviations from a supplied mean.
A clear answer. Here’s how.
Z = (value−mean)/standard deviation. The supplied standard deviation must be positive. A z-score alone does not establish a normal distribution, percentile or statistical significance.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Observed value
- 85
- Reference mean
- 70
- Reference standard deviation
- 10
Example result
- Z-score
- 1.5