Normal distribution calculator

Find the z-score and the probabilities above and below a threshold.

Numbers Stateless

Quick guide

Try an example

You enter

Mean
50
Standard deviation
10
Threshold
50

You get

Z-score
0
Probability below the threshold
0.5
Probability above the threshold
0.5
How it works and limits

Enter the mean, a positive standard deviation and a threshold. Probabilities range from 0 to 1.