Pregnancy Calculator
Track pregnancy milestones week by week from your due date.
How pregnancy is dated
Clinicians count from the last menstrual period (LMP), not conception — so 'week 4' is only about two weeks after fertilization. Full term runs 39–40 weeks; a first-trimester ultrasound often refines the date by a few days and takes precedence over the LMP estimate.
Trimester landmarks
The first trimester (to 13 weeks) covers organ formation and most morning sickness; the second (to 27 weeks) usually brings energy back and the anatomy scan around week 20; the third is growth and lung maturation. Only ~4% of babies arrive exactly on their due date.
Frequently asked questions
- How does the Pregnancy Calculator work?
- Track pregnancy milestones week by week from your due date.
- Is the Pregnancy Calculator free to use?
- Yes. The Pregnancy Calculator is completely free, runs entirely in your browser, and requires no account or sign-up. Your inputs never leave your device.
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