Tools

Count sentences, words and average words per sentence in text.

Convert any numerator and denominator to a percentage.

Simplify a two-number ratio using the greatest common divisor.

Calculate the arithmetic average of a list of numbers.

Calculate a course grade from assessments with different weights.

Convert marks obtained and total marks into a percentage.

Calculate apparent volume of distribution from amount in body and plasma concentration.

Calculate clearance from elimination rate constant and volume of distribution.

Calculate first-order elimination rate constant from half-life.

Calculate absorbance, concentration, path length or molar absorptivity.

Convert dilute aqueous concentration between ppm and mg/L under the usual density approximation.

Convert concentration between mg/mL and percent weight/volume.

Calculate volume/volume percentage concentration.

Calculate weight/volume percentage concentration.

Calculate solution normality from equivalents and final volume.

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

Adjust a simple-random sample size for clustering.

Calculate cumulative incidence from new cases and population at risk.

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

Calculate absolute risk reduction and number needed to treat.

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

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

Estimate a confidence interval around a sample mean.

Estimate a confidence interval for a sample proportion.