# Confidence Interval Calculator

A confidence interval calculator can easily calculate the confidence interval of sample size, standard deviation, and mean.

**Confidence Interval Calculator**

Confidence interval calculator is used to find out the confidence interval of a particular sample, mean, sample size, and standard deviation. Furthermore, the confidence interval includes the range of values that are derived from sample statistics. Before calculating the confidence interval, you must know the basic parameters of your sample including standard deviation, mean value, and sample size. After that **calculate** the standard error and margin of error.

Moreover, in the case of using different confidence levels, you need to calculate the z-score with the help of the Z-score **calculator**. For calculating the z-score, you will need to first decide the confidence level and then calculate its probability. After that, analyze the area of the z-score with the help of the normal distribution curve. Once the z-score is calculated, you can simply put its values in the equation to get the margin of error. Furthermore, we also added a **loan calculator** and many other daily used **web tools** for ease of our visitors.

**How To Calculate Confidence Interval?**

For calculating the confidence level, you will first need to identify the sample size. After that, find the mean value of that sample size and then determine its **standard deviation**. The next step is to select the confidence level and the most commonly used one is 95%. Look at the statistical table and then find the z-score. After that, you have to compute the standard error and then multiply the value with the z-score in order to get the margin of error. Lastly, add and subtract the value of the **margin** of error from the mean value, and your confidence level is obtained.

By using the Convertzen Confidence Interval **Calculator website**, you can easily and quickly calculate the confidence interval. Moreover, the values that lie outside the intervals are the ones that are rejected. On the other hand, the values that lie inside the intervals are accepted. Hence when the interval covers the null hypothesis, it cannot be rejected. Furthermore, for assessing the effect sizes, you can also construct various confidence intervals at different levels from the same set of data. For this, the best approach is to calculate the severity criterion in order to make a decision about null more acceptable.

**FAQs**

**How do I calculate a 95% confidence interval?**

For calculating a 95% confidence interval, you have to take the estimate for an unknown population mean. This means that 95% of probability in the confidence interval contains true population means.

**What is the z value in statistics?**

Z-score is the value of the relationship to the mean of the various groups of values. This is measured in terms of standard deviations from the mean value. If the z value of a relationship is 0 then it indicates that the data point’s score is similar to the mean value.

**Conclusion**

Confidence interval calculator is used to calculate the confidence interval of a sample size, mean and standard deviation. However, for calculating the confidence interval, make sure you know the parameters of the sample that includes standard deviation, mean, and sample size. Furthermore, while calculating, make sure to identify the mean value of your selected sample size and then after that determine the standard deviation. Apart from using the calculator, you can also calculate the confidence interval with the help of the calculator.net website.