calculatorsonline.co.uk
Z Score Calculator
Calculate a z-score and the percentile of a value in a normal distribution.
chart Free Online Tool
⚡ Instant Results
📊 Clear Comparison
🔒 100% Free Tool
Z-score
Compare Your Options And Get Clear Answers
Calculate a z-score and the percentile of a value in a normal distribution.
Z Score Estimator
Enter your numbers below for an instant estimate.
0
💡 Tip: z = (x – mean) / standard deviation.
How It Works
Key concepts behind this calculator
1
Enter Values
Fill in each field with your own numbers.
2
Calculate
Results update as you change the inputs.
3
Review
Read the breakdown and the explanation.
4
Adjust
Change values to compare scenarios.
Quick Reference Guide
Z Quick Guide
Typical values for reference.
| x | Mean | SD | z |
|---|---|---|---|
| 55 | 70 | 8 | -1.875 |
| 70 | 70 | 8 | 0.000 |
| 78 | 70 | 8 | 1.000 |
| 94 | 70 | 8 | 3.000 |
| Rule of Thumb | Check inputs | Use as a guide | Round sensibly |
Common Questions
Z Score Calculator FAQ
Answers to common questions about this calculator.
The number of standard deviations a value lies from the mean.
Beyond plus or minus 2 is unusual for a normal distribution.
z = (x – mean) / standard deviation.
It is an estimate based on the inputs you enter. Check real quotes, labels or official guidance for important decisions.