Standard Deviation Calculator
Calculate sample or population standard deviation with mean, variance, range, quartiles, median and IQR.
Open calculatorWhat this category helps with
Statistics calculators help with questions where a number is useful but the assumptions matter. Start with the calculator closest to your question, then use the linked guide or formula page when units, rates, dates, local rules or source data could change the answer.
Best starting points
Mean Calculator
Calculate arithmetic mean from a list of numbers.
Open calculatorMedian Calculator
Calculate the median from a list of numbers.
Open calculatorRange Calculator
Calculate statistical range from a list of numbers.
Open calculatorMode Calculator
Find the most frequent value in a list.
Open calculatorSample Size Calculator
Estimate sample size for a proportion with confidence z and margin of error.
Open calculatorHow to choose the right calculator
- Use a broad calculator first when you need a quick estimate.
- Use a more specific calculator when rates, units, dates, eligibility or fees change the answer.
- Read assumptions before comparing results across calculators or external sources.
- For current-data topics, confirm the data source and date before relying on the result.
Calculators
Standard Deviation Calculator
Calculate sample or population standard deviation with mean, variance, range, quartiles, median and IQR.
Open calculatorMean Calculator
Calculate arithmetic mean from a list of numbers.
Open calculatorMedian Calculator
Calculate the median from a list of numbers.
Open calculatorRange Calculator
Calculate statistical range from a list of numbers.
Open calculatorMode Calculator
Find the most frequent value in a list.
Open calculatorSample Size Calculator
Estimate sample size for a proportion with confidence z and margin of error.
Open calculatorProbability Calculator
Calculate simple probability from favorable and total outcomes.
Open calculatorStatistics Calculator
Calculate mean and basic spread from count, sum and sum of squares.
Open calculatorPermutation and Combination Calculator
Calculate nPr and nCr for non-negative integers.
Open calculatorZ-score Calculator
Calculate z-score from value, mean and standard deviation.
Open calculatorConfidence Interval Calculator
Calculate a normal-approximation confidence interval.
Open calculatorAverage Calculator
Calculate average from sum and count.
Open calculatorP-value Calculator
Approximate two-tailed p-value from a z-score.
Open calculator