# Z Critical Value Calculator

In Statistics, the critical values are used to determine the probability of any particular variable. A critical value of z is used when the sampling distribution is normal, or close to normal. The below-given Z critical value calculator will help you to calculate critical Z value.

## Calculate Critical Z Value

In Statistics, the critical values are used to determine the probability of any particular variable. A critical value of z is used when the sampling distribution is normal, or close to normal. The below-given Z critical value calculator will help you to calculate critical Z value.

Code to add this calci to your website

#### Formula Used:

Probability (p): p = 1 - α/2.
A critical value is a line on a graph that splits the graph into sections. A z critical value is used when there is a normal sampling distribution, or when close to normal. It is represented as z_{a}, where the alpha level, a, is the area in the tail. For example, z_{.7} = 0.5244. The Z Critical Value or the z-score is equal to the number of standard deviations from the mean. Use our online Z critical value calculator to calculate critical z value for probability values. Just enter a Probability Value (α) between zero and one to calculate critical value. To calculate the critical z value just divide alpha (α) by 2 (two) and minus the answer with 1.

#### Example

**What is the critical z value of α = 0.9**

z = 1 - (0.9/2)

= 1 - 0.45
= 0.55
Referring the Z table, we have the Z critical value as 1.2816.