Use health calculators as estimates with clearly stated limits. Read the formula and context before interpreting a result.
Calculate adult body mass index using metric or imperial measurements.
Estimate resting energy expenditure with the Mifflin–St Jeor equation, then apply your selected activity factor to estimate total daily expenditure.
Estimate a calendar ovulation date and a broad surrounding window from the first day of a period and usual cycle length..
Estimate a due date from the first day of the last menstrual period, adjusted for your usual cycle length.
Editorial responsibility: Nicolas Belotti · Methods and testing · Report an error
English edition: 16 September 2026.