Pregnancy lasts approximately 40 weeks (280 days) from the first day of the last menstrual period.
First trimester: weeks 1-12. Second: weeks 13-26. Third: weeks 27-40.
This tool is most useful for tracking trends rather than obsessing over a single data point. Run the calculation monthly with consistent measurement conditions to see whether your metric is moving in the right direction.
Many users apply adult health classifications to children and teenagers, which is incorrect. Paediatric norms for height, weight, BMI, and body composition are age-and-sex-specific. Use age-appropriate reference tools for anyone under 18.
A nurse calculates a patient's health metric during a routine assessment, then uses the result alongside other clinical indicators to contextualise the finding — correctly treating the number as one data point among several rather than a standalone answer.
Full-term is 39-40 weeks. Early term is 37-38 weeks. Post-term is after 42 weeks.
CalcPlanet – Free Online Calculators
725+ free calculators and 108 tools for math, money, health, and everyday life. Instant results, verified formulas, no sign-up.
By CalcPlanet Editorial · Reviewed against our Editorial Standards and Formula Sources.
CalcPlanet calculators are free, privacy-first, and formula-reviewed.
Editorial Standards · Formula Sources · Privacy · Terms · Contact
