Due Date Calculator
Enter your last menstrual period or conception date to estimate when your baby will arrive. Based on the Naegele's Rule method used by OB/GYNs.
📅 Last Period (LMP)
🔬 Conception Date
🩺 IVF Transfer Date
Select the first day of your most recent menstrual period
Most cycles are 28 days. Adjust if yours differs.
Your Estimated Due Date
October 22, 2026
That's a Thursday! 🎉 You're currently 13 weeks, 6 days pregnant.
13+6
Weeks Pregnant
183
Days to Go
T2
Current Trimester
📋 Key Milestones
Conception (estimated)Jan 29, 2026Week 2
First heartbeat detectableFeb 26, 2026Week 6
End of 1st TrimesterApr 16, 2026Week 13
Anatomy Scan WindowMay 21 – Jun 18Week 18–22
Viability MilestoneJul 2, 2026Week 24
3rd Trimester BeginsJul 16, 2026Week 28
Full Term (safe to deliver)Oct 1, 2026Week 37
🎉 Estimated Due DateOct 22, 2026Week 40
How Is My Due Date Calculated?
We use Naegele's Rule, the same method your OB/GYN uses. Starting from the first day of your last menstrual period (LMP), we add 280 days (40 weeks). If your cycle is longer or shorter than 28 days, we adjust accordingly.
Keep in mind: Only about 5% of babies are born on their actual due date. Most arrive within a 2-week window around the estimated date. Your due date may be adjusted after an early ultrasound measurement.
Frequently Asked Questions
How accurate is a due date calculator? +
Due date calculators provide an estimate within ±2 weeks. First-trimester ultrasounds (7–11 weeks) are the most accurate dating method, typically within ±5 days. Your provider may adjust your due date based on ultrasound measurements.
What if I don't know my last period date? +
If you're unsure of your LMP, your healthcare provider can estimate your due date using an early ultrasound measurement (crown-rump length). You can also use the "Conception Date" or "IVF Transfer Date" tabs above if those dates are known.
Can my due date change? +
Yes. Your doctor may adjust your due date after your first ultrasound if the baby's measurements don't match your LMP-based date. A difference of more than 7 days in the first trimester typically warrants a revision.
More Pregnancy Tools
Free calculators and trackers to support your journey
Contraction Timer
Track timing & duration
Kick Counter
Monitor baby's movements
Growth Chart
WHO growth percentiles
Name Finder
Search 115K+ names
⚕️ Medical Disclaimer: This tool provides an estimate only and does not constitute medical advice. Due date calculations are most accurate when confirmed by your healthcare provider through ultrasound dating.