Z-Score Calculator
Z = (Value − Mean) ÷ Standard deviation(70−50)÷10=2.0
Free online tool
Z-Score Calculator
Enter a value, the population mean and standard deviation.
Instant calculation
Z-Score Calculator
Enter a value, the population mean and standard deviation.
Your result
Calculation
Your numbers stay in this browser. Nothing is uploaded or saved.
Three clear steps
How to use this calculator
- 01
Enter value
Type the data point to evaluate.
- 02
Enter mean
Type the population mean.
- 03
Enter standard deviation
Type the population standard deviation.
The formula
How this calculation works
A z-score tells how many standard deviations a value is from the mean. Positive = above mean, negative = below.
Check the method
Worked examples
Each example follows the same formula used by the calculator.
Value=70, mean=50, SD=10 — z-score?
(70−50)÷10=2.0Z = 2.0 (2 SDs above mean)Common questions
Questions about this calculation
What is the Z-Score Calculator?
The Z-Score Calculator helps you calculate the z-score (standard score) of a value in a distribution. Enter your values and select Calculate to get an instant result.
How is the result calculated?
A z-score tells how many standard deviations a value is from the mean. Positive = above mean, negative = below.
Can you show an example?
Example: Value=70, mean=50, SD=10 — z-score? — Z = 2.0 (2 SDs above mean).
Is my data saved when I use the Z-Score Calculator?
No. All calculations run locally in your browser. Your inputs and results are never uploaded, stored or shared with anyone.
Is the Z-Score Calculator free to use?
Yes. The Z-Score Calculator is completely free. No account, sign-up or payment is required. It works on mobile, tablet and desktop.
Continue calculating