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SDCalc

Statistical Calculators

Professional-grade tools for data analysis and statistical computation.

Cohen's d Effect Size Calculator Helper

Use the calculator to summarize each group from raw data, then compute the mean difference, sample SD, and sample size inputs needed for Cohen's d and pooled standard deviation workflows. Useful for A/B tests, classroom comparisons, and two-group research reporting.

Batting Average Calculator

Calculate batting average from raw hit results online. Enter plate appearance outcomes as hits and outs to get batting average plus mean, variance, standard deviation, count, and range for lineup and game-by-game analysis.

Weighted Average Calculator

Calculate the average and spread of weighted data by entering raw values or frequency-expanded repeated values. Use the results with mean, variance, standard deviation, standard error, count, min, max, and range for quick statistics checks.

T-Test Calculator Helper

Prepare the summary statistics needed before a one-sample or two-sample t-test. Built for lab analysts, classroom researchers, and QC engineers reviewing 20-100 measurements who need mean, sample standard deviation, standard error, and sample size before moving into p-value, confidence interval, or pooled standard deviation workflows.

Critical Value Calculator Helper

Prepare the summary statistics needed before looking up a z critical value or t critical value. Built for analysts, instructors, and QC engineers checking 20-100 raw measurements who need mean, sample standard deviation, standard error, and sample size before moving into p-value, confidence interval, margin of error, or t-test workflows.

P-Value Calculator Helper

Use the calculator to summarize raw sample data before computing a p-value. Get the mean, sample standard deviation, standard error, sample size, and z-score or t-test inputs needed for hypothesis testing, confidence intervals, and significance checks.

Margin of Error Calculator

Calculate the mean, sample standard deviation, and standard error from raw data online to support margin of error checks, confidence interval setup, and sample size planning.

Min Max Calculator

Calculate the minimum and maximum of your dataset from raw values online. Instantly get min, max, range, mean, variance, standard deviation, and standard error in one workflow.

Range Calculator

Calculate the range of your data from raw values online. Instantly get minimum, maximum, range, mean, variance, standard deviation, and standard error in one workflow.

Grade Average Calculator

Calculate a grade average from raw scores online. Enter test, quiz, homework, or assignment grades to get the mean plus standard deviation, variance, standard error, count, min, max, and range in one workflow.

Mean and Standard Error Calculator

Calculate the sample mean and standard error from raw data online. Enter your values to get the average, sample standard deviation, standard error of the mean, variance, count, min, max, and range in one workflow.

Mean and Standard Deviation Calculator

Calculate mean and standard deviation from raw data online. Enter your values to get the average, sample standard deviation, population standard deviation, variance, standard error, and range in one workflow.

Mean and Variance Calculator

Calculate mean and variance from raw data online. Enter your values to get the average, sample variance, population variance, standard deviation, standard error, and range in one workflow.

Standard Deviation and Standard Error Calculator

Calculate standard deviation and standard error from raw data online. Enter your values to get sample SD, population SD, variance, mean, count, min, max, and range in one workflow.

Confidence Interval Standard Deviation Calculator

Calculate the mean, sample standard deviation, and standard error from raw data online. Use the results to check spread, estimate precision, and move faster into confidence interval and hypothesis test work.

Standard Error of the Mean Calculator

Calculate the standard error of the mean (SEM) from raw sample data online. Enter your values to get sample standard deviation, sample size, mean, and SEM for faster confidence interval and hypothesis test work.

Relative Standard Deviation (RSD) Calculator Online

Calculate relative standard deviation (RSD%) from raw data or mean and SD. Get instant coefficient of variation results with steps.

Weighted Standard Deviation Calculator

Calculate the weighted standard deviation for your data set with our free online calculator. Enter your values and weights to get instant results, including the formula and step-by-step calculations.

Pooled Standard Deviation Calculator

Calculate the pooled standard deviation for two or more groups instantly. Enter your sample sizes, means, and standard deviations to get precise results with step-by-step explanations.

Population Standard Deviation Calculator

Calculate the population standard deviation of your dataset instantly. Eliminate manual math errors and quickly determine the exact spread of your entire population for confident analysis.

Sample Standard Deviation Calculator

Compute the sample standard deviation of any data set instantly. Accurately measure your sample's data spread to make confident statistical inferences without manual formula errors.

Outlier Calculator

Detect outliers using IQR, Z-score, and Modified Z-score (MAD) methods with visual identification.

Sample Size Calculator

Determine the required sample size for surveys and experiments with confidence level and margin of error.

Correlation Calculator

Calculate Pearson and Spearman correlation coefficients, covariance, and linear regression analysis.

Percentile Calculator

Compute percentiles, quartiles, deciles, and interquartile range with visualization of data distribution.

Mean, Variance, and Standard Deviation Calculator

Calculate mean, variance, and standard deviation from raw data online. Enter your values to get the average, sample or population variance, standard deviation, standard error, count, min, max, and range in one workflow.

Mean and Variance Calculator

Calculate mean and variance from raw data online. Enter your values to get the average, sample variance, population variance, standard deviation, standard error, and range in one workflow.

Mean Calculator

Calculate arithmetic, geometric, harmonic mean, median, mode, trimmed mean, and RMS with step-by-step solutions.

Descriptive Statistics

Get a complete statistical summary including mean, median, mode, range, and quartiles.

Probability Distribution

Visualize and calculate probabilities for normal, binomial, and other statistical distributions.

Test Score Standard Deviation Calculator

Calculate standard deviation for test scores from raw results online. Enter exam, quiz, or assessment scores to get mean, sample or population SD, variance, standard error, count, min, max, and range in one workflow.

Z-Score Standard Deviation Calculator

Prepare the mean and standard deviation inputs needed for z-score work from raw data. Built for teachers checking class scores, QC engineers reviewing 20-100 part measurements, and analysts moving from a dataset summary into z = (x - mean) / SD, percentile, or outlier checks.

Z-Score Calculator

Convert raw scores to standardized z-scores and calculate percentile rankings.

Sample Variance Calculator

Calculate sample variance from raw data online. Enter your values, use sample mode, and get s^2 along with mean, standard deviation, standard error, and range in one workflow.

Population Variance Calculator

Calculate population variance from raw data online. Enter your full population values to get σ^2, population standard deviation, mean, count, min, max, and range in one workflow.

Variance and Standard Deviation Calculator

Calculate variance and standard deviation from raw data online. Enter your values to get sample variance, population variance, sample SD, population SD, mean, standard error, count, min, max, and range in one workflow.

Variance Calculator

Compute variance for your dataset with detailed step-by-step breakdowns and interpretation.