Tools

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

Standardize a value using a mean and standard deviation.

Calculate CV as standard deviation relative to the mean.

Calculate sample or population variance from raw data.

Calculate sample or population standard deviation from raw values.

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

Find the median of a set of numeric values.

Calculate the arithmetic mean of a list of numbers.

Calculate a weighted mean from values with different percentage or numeric weights.

Convert common length, mass, volume and temperature units with a fast multi-category converter.

Calculate the number of calendar days and weeks between two dates.

Calculate exact age in years, months and days between a date of birth and a selected date.

Calculate the amount remaining after a given time for a quantity undergoing first-order half-life decay.

Use C1V1 = C2V2 to calculate the stock volume required for a target concentration and final volume.

Calculate solution molarity from solute mass, molecular weight and final solution volume.

Estimate how long a text will take to read from its word count and selected reading speed.

Count characters with spaces, characters without spaces and words in any text.

Count words, characters, sentences and estimated reading time instantly as you type.

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

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

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

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

Solve common percentage questions including percent of a number, percent change and what percent one number is of another.

Find the score you need on a final exam or remaining assessment to reach a target course grade.