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Statistics Calculators

Z-Score Calculator

Convert a raw score to a z-score from the mean and standard deviation, with the percentile and p-values from the normal curve.

Enter values

Results update as you type.

Result

z-score

1.5

Percentile
93.319%
P(Z < z)
0.933193
P(Z > z)
0.066807
Two-tailed p-value
0.133614
Step-by-stepShow
  1. z = (85 − 70) ÷ 10 = 1.5

About the Z-Score Calculator

Convert a raw score to a z-score from the mean and standard deviation, with the percentile and p-values from the normal curve.

Also known as: standard score, z value, z table calculator, normal distribution percentile, p value from z.

How to use this calculator

  1. Enter raw score x, mean μ, standard deviation σ.
  2. The result updates instantly as you type — press Calculate (or Enter) at any time.
  3. Open “Step-by-step” to see how the answer was worked out.
  4. Use Copy result or Share to save the answer or send a link with your inputs.

Formula

z = (x − μ) / σ

Worked example

Using the values pre-filled in the calculator above:

  • Raw score x = 85
  • Mean μ = 70
  • Standard deviation σ = 10

the calculator returns:

  • z-score: 1.5
  • Percentile: 93.319%
  • P(Z < z): 0.933193
  • P(Z > z): 0.066807

Working

  1. z = (85 − 70) ÷ 10 = 1.5