Due Date Calculator
Estimate pregnancy due date based on last menstrual period.
What Is the Due Date Calculator?
A due date calculator estimates when your baby will arrive based on your last menstrual period or conception date. Most pregnancies last about 40 weeks (280 days) from the first day of your last period.
The Formula
Due Date = LMP + 280 days (40 weeks).
Example
If your last period started on March 15, 2026, and you have a typical 28-day cycle, your estimated due date would be around December 20, 2026. Only about 5% of babies arrive exactly on their due date.
Common Uses
Pregnancy planning, prenatal appointment scheduling, milestone tracking.
Frequently Asked Questions
How does the Due Date Calculator work? ▼
The Due Date Calculator uses standard medical formulas based on peer-reviewed research. Enter your measurements and the calculator provides your results instantly with reference ranges and explanations.
Is this calculator a substitute for medical advice? ▼
No, this calculator provides estimates for informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a healthcare provider for medical decisions.
How accurate are health calculators? ▼
Health calculators provide estimates based on population averages. Individual results vary based on genetics, body composition, and other factors. These are useful screening aids, not diagnostic tools.
Common Mistakes to Avoid
- ⚠ Treating calculator results as medical diagnoses rather than estimates.
- ⚠ Using results as a substitute for professional medical consultation.
- ⚠ Not considering individual factors like genetics and medical history.