Health Tools

Due Date Calculator

Calculate your fertility window or estimate your pregnancy milestones with our privacy-first tools.

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How is your due date calculated?

Standard due date calculations are based on your Last Menstrual Period (LMP) and assume a regular 28-day cycle. A typical human pregnancy lasts approximately 40 weeks (280 days) from the first day of the LMP. Doctors commonly apply Naegele's Rule: add 7 days to the first day of your last period, subtract three months, and add one year.

How do IVF transfer due date calculations differ?

If you conceived through In Vitro Fertilization (IVF), your due date is calculated using the date of embryo transfer rather than your last period. The calculation adjusts for the exact age of the embryo: add 263 days for a 3-day embryo transfer, and 261 days for a 5-day embryo transfer.