Convert between common power units including watts, kilowatts, megawatts, horsepower, and BTU per hour.
Compute McNemar's chi-square statistic for paired-categorical data (e.g. yes/no before vs after a treatment in the same...
Compute the sample skewness — the third standardized moment of a distribution — from the centred third moment m₃ = E[(X...
Compute the network throughput (Mbps) required to transfer a file of a given size in a target time, and the time require...
Convert any angle between degrees, radians, gradians, and turns.
Calculates the Sharpe Ratio of a portfolio from its return, the risk-free rate, and its standard deviation to measure ri...
Compute the centripetal force required to keep an object moving in a circle of given radius at a given speed.
Calculates a weight-based medication dose (e.g. mg/kg) and checks it against a maximum dose ceiling. Used for paediatric...
Compute the one-way ANOVA F statistic, between-group MSB, and within-group MSW for three independent samples directly fr...
Compute the mean absolute error (MAE) and root-mean-square error (RMSE) of up to five (actual, predicted) pairs — useful...
Volume, lateral surface area, and total surface area of a right circular cylinder from radius and height.
Calculates the series current-limiting resistor value needed to protect an LED from a supply voltage given its forward v...
Every "X% of Y" problem, every "what percent of", every percent-change question — written out the way you'd actually say them.
Daniel Oh
Standard deviation is "average distance from the average". That one sentence covers 90% of everything you ever need to remember about it.
Daniel Oh