Field estimates from a tape measure disagree with each other and with a DEXA scan for reasons that are usually knowable, not mysterious — which formula was used, which measurements it depends on, and where it tends to run high or low. Every calculator here names its method and shows the arithmetic, so a result is something you can check rather than take on faith.
Health & Fitness calculators
Body Fat Calculator
Navy, BMI and 3-site skinfold body fat estimates, with every step shown.
Health & FitnessHeight Comparison
Two or more people drawn side by side at one shared scale.
Health & FitnessRucking Calorie Calculator
Energy cost of a loaded march, by the Pandolf equation.
Health & FitnessMiscarriage Statistics
Published figures by age and week, with their sources.
Health & Fitness