Confidence Interval Calculator

Quickly calculate the average (mean) of a set of numbers. Simply enter your numbers to find their central tendency.

Calculate the Mean Absolute Deviation (MAD) of a data set, which measures the average distance between each data point and the mean. A simple measure of variability.

Calculate the mean, median, mode, and range for any set of numbers. A fundamental tool for understanding the central tendency and spread of data.

Calculate probabilities and Z-scores for a normal distribution (bell curve). A powerful statistical tool for analyzing continuous data.

Calculate the p-value from a Z-score, t-score, or other statistical test. Determine the statistical significance of your results in hypothesis testing.

Calculate the percent error between an experimental value and a theoretical value. A fundamental calculation in science to determine the accuracy of a measurement.

Calculate permutations (nPr) and combinations (nCr) for a set of items. An essential tool for probability, statistics, and combinatorics.

Determine the minimum sample size needed for a survey or experiment. Calculate the sample size for a given population, confidence level, and margin of error.

Estimate your self-employment taxes as a freelancer or independent contractor. Helps you plan for quarterly tax payments and avoid surprises.

Project the growth of your 401(k) retirement savings over time. See how contributions, employer match, and investment returns can impact your nest egg.

Project the future value of a 529 college savings plan. See how your contributions can grow over time to help fund educational expenses.

Quickly find the exact date that was 90 days before today or any other specified date. Useful for tracking deadlines and timelines.

Convert your A1c level to an Estimated Average Glucose (eAG) number. A vital tool for individuals with diabetes to understand their blood sugar control.

Calculate the Alcohol By Volume (ABV) of your homebrew beer, wine, or cider by providing the original and final gravity readings.

Convert between units of angular acceleration.

Convert between units of acceleration like m/s² and g-force.