Free online calculators organised from broad topics down to specific tools.

Use this energy availability calculator to calculate energy availability, screen for low energy availability and RED-S risk.

Use this calorie deficit calculator to estimate maintenance calories, choose a safe daily deficit, and plan realistic weight-loss calories.

Use this body shape calculator to identify your body type from bust, waist, and hip measurements, then interpret waist-to-hip and waist-to-height ratio context.

Use this Easter date calculator to find when Easter Sunday falls, compare Western and Orthodox Easter.

Use this TDEE calculator to estimate maintenance calories from age, body size, sex, and activity level, then compare practical cutting and gaining targets.

Use this MET calculator to convert metabolic equivalent values into calories burned, gross vs net exercise calories, and weekly MET minutes for walking.

Use this sweepstake generator to randomly assign teams, prizes, horses, or numbers to names for office pools, World Cup draws, and other informal sweepstakes.

Use this anti-inflammatory diet score calculator to see whether your weekly meals lean toward anti-inflammatory foods or a more inflammatory pattern.

Use this GKI calculator to calculate your glucose ketone index from blood glucose and ketones, compare common bands.

Use this average speed calculator to work out trip average speed from distance and time, compare moving speed with stop-inclusive averages.

Use this container loading calculator to estimate how many boxes fit in a 20ft, 40ft, or high-cube shipping container, compare volume and payload limits.

Use this roof snow load calculator to convert mapped ground snow load into balanced flat-roof load, slope-adjusted roof load.

Calculate the arc length, sector area, chord length, and fraction of circle from radius and central angle.

Use the arccot calculator to turn a cotangent value into its principal angle in degrees or radians, with exact checkpoints, range guidance.

Calculate exact P(X = k), cumulative P(X ≤ k), upper-tail P(X ≥ k), strict upper-tail P(X > k), mean, variance, and normal-approximation context from n, k.

Calculate capacitance from charge and voltage, from plate geometry, or from frequency and reactance, with supporting energy, dimension.