This calculator will compute the 99%, 95%, and 90% confidence intervals for the mean of a normal population, given the sample mean, the sample size, and the sample standard deviation.

An easy confidence interval calculator using a Z statistic to estimate a population mean from a single sample. Provides full details of workings.

Use this calculator to compute the confidence interval or margin of error, assuming the sample mean most likely follows a normal distribution. Use the Standard Deviation Calculator if you have raw data only. A confidence interval is a statistical measure used to indicate the range of estimates within which an unknown statistical parameter is likely to fall. If the parameter is the population mean, the confidence interval is an estimate of possible values of the population mean.

Rounding - when the number is bigger ... format 88.1234 to 88.12 , and 0.001234 to 0.0012. ... The confidence interval is the range in which the population parameter is most likely to be found....

February 24, 2016 - Use this calculator to determine a confidence interval for your sample mean where you are estimating the mean of a population characteristic (e.g., the mean blood pressure of a group of patients).

Statistical calculators, sample size, free, confidence interval, proportion, mean

Statistical calculators, sample size, free, confidence interval, proportion, mean

Enter how many in the sample, the mean and standard deviation, choose a confidence level, and the calculation is done live. Read Confidence Intervals to learn more. ... Use the Standard Deviation Calculator to calculate your sample's standard deviation and mean. Caution: you should really use the standard deviation of the entire population!

Compute confidence intervals around continuous data using either raw or summary data.

Calculates the confidence interval for the difference between two population means: equal variances, unequal variances, and paired groups.

December 25, 2023 - CONFIDENCE INTERVAL Calculator WITH DATA (sigma unknown) Type in the values from the data set separated by commas, for example, 2,4,5,8,11,2. Then type in the confidence level, CL, and hit Calculate. Write the confidence level as a decimal.

Confidence Interval without using calculator function T-interval:

September 5, 2025 - Easily calculate the confidence interval for a population mean with our user-friendly Confidence Interval Calculator.

The Confidence Interval Calculator calculates both the lower and upper bounds of the interval in which the estimate of a population mean (μ) is likely to fall.

October 11, 2025 - Enter the Standard Deviation.: Depending on your distribution choice, this value is either a sample estimate or a known population value. Enter the Sample Size. Enter the Confidence Level: 95 is the default. Use a number between 0 and 100. For example, use 90, not 0.90.

Do you need to find a Confidence Interval Calculator quickly? Input your data to obtain the metric, step-by-step calculation, Python and R codes, and more. Calculate now.

September 18, 2025 - Thus, the confidence interval is equal to the sample mean x̄ plus or minus the z-score for the confidence level z times the population standard deviation σ divided by the square root of the sample size n. Ideally, the standard deviation of ...

This utility calculates confidence limits for a population proportion for a specified level of confidence. Inputs are the sample size and number of positive results, the desired level of confidence in the estimate and the number of decimal places required in the answer. The program outputs the estimated proportion plus upper and lower limits of the specified confidence interval...

Performs unpaired t test, Weldh's t test (doesn't assume equal variances) and paired t test. Calculates exact P value and 95% confidence interval. Clear results with links to extensive explanations.

For example, an 85% confidence interval indicates that if you sampled your population numerous times, you would capture the true result within the confidence interval in approximately 85% of the samples. Standard deviation: Use standard deviation to measure how spread out your data is from the average or mean. If the standard deviation is low, most data points are close to the average; if it's high, data is more spread out. ... Use our survey sample size calculator or the sample size formula to calculate your sample size.