Pregnancy Due Date Calculator
Calculate your estimated due date, current pregnancy week, trimester, and conception date based on LMP (Last Menstrual Period) or known due date. Track your pregnancy progress with a visual progress bar.
How to Use This Calculator
- Select whether to calculate From LMP (Last Menstrual Period) or From Due Date.
- Enter the relevant date and an optional reference date (defaults to today).
- Click Calculate to see your due date, weeks pregnant, trimester, conception date, and progress bar.
Formula
Conception: Typically occurs ~14 days after LMP. Trimesters: First (Weeks 1–12), Second (Weeks 13–26), Third (Weeks 27–40).
Examples
Due Date = Oct 8, 2026. Conception ≈ Jan 15, 2026.
LMP = Mar 20, 2026. Conception ≈ Apr 3, 2026.
If LMP was 20 weeks ago, you are approximately 20 weeks pregnant (end of second trimester).
Frequently Asked Questions
How accurate is the due date calculation?
Only about 5% of babies arrive on their exact due date. The due date is an estimate; most babies arrive between 38–42 weeks.
What is Nägele's rule?
Nägele's rule estimates the due date by adding 280 days (40 weeks) to the first day of the last menstrual period.
Can I calculate from conception date?
This calculator estimates conception as LMP + 14 days. For IVF or known conception dates, use the "From Due Date" mode.
What if my cycle is longer or shorter than 28 days?
The standard calculation assumes a 28-day cycle. For longer/shorter cycles, adjust accordingly or consult your healthcare provider.