Statistics Calculators

Calculate CV as standard deviation relative to the mean.

Calculate standardized mean difference for two independent groups using pooled standard deviation.

Adjust a simple-random sample size for clustering.

Calculate cumulative incidence from new cases and population at risk.

Calculate a proportion margin of error for a selected confidence level.

Calculate the arithmetic mean of a list of numbers.

Estimate a confidence interval around a sample mean.

Find the median of a set of numeric values.

Find the most frequently occurring value or values in a dataset.

Inflate a sample size to allow for expected non-response.

Calculate absolute risk reduction and number needed to treat.

Calculate an odds ratio and approximate 95% confidence interval from a 2×2 contingency table.

Calculate positive and negative predictive values from a 2×2 table.

Calculate prevalence from the number of existing cases and population size.

Estimate a confidence interval for a sample proportion.

Calculate risk ratio and an approximate 95% confidence interval from exposed and comparison groups.

Estimate a survey sample size from confidence level, margin of error, expected proportion and population size.

Calculate diagnostic sensitivity and specificity from a 2×2 table.

Calculate sample or population standard deviation from raw values.

Calculate sample or population variance from raw data.

Standardize a value using a mean and standard deviation.