Calculate your baby's due date and pregnancy milestones based on your last menstrual period (LMP). Get accurate pregnancy timeline and trimester information.
All calculations run locally. Your data stays private — never leaves your device.
How to Use
1
Enter LMP Date
Select first day of last menstrual period
2
Click Calculate
Press calculate to see your results
3
View Due Date
See your baby's estimated due date
4
Track Progress
Check current week and trimester
Features
Instant Results
Get calculations in real-time
100% Private
All processing in your browser
Complete Timeline
Trimester dates included
Conception Date
Estimated conception day
Unlimited Use
No limits, no registration
Key Milestones
Week 4-5
Positive test
Week 8-10
First ultrasound
Week 12
End of 1st trimester
Week 18-22
Anatomy scan
Week 24-28
Glucose test
Week 37-40
Full term
Why Use Our Due Date Calculator?
Instant Results
Get your due date instantly
100% Private
All calculations happen locally
Complete Timeline
Trimester breakdown included
Any Device
Works perfectly on all devices
Frequently Asked Questions
How is due date calculated?
Due date is calculated by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP). This is the standard Naegele's rule used by doctors.
How accurate is due date?
Only about 5% of babies are born exactly on their due date. Most arrive between 37 and 42 weeks. The due date is an estimate, not a guarantee.
What if I don't know my LMP?
If you're unsure of your LMP, an ultrasound in the first trimester can help determine your due date more accurately based on baby's measurements.
What is conception date?
Conception (when the egg is fertilized) typically occurs about 14 days after the first day of your LMP, around the time of ovulation.
What are the trimesters?
Pregnancy is divided into three trimesters: First (weeks 1-12), Second (weeks 13-26), and Third (weeks 27-40). Each trimester has different milestones.
Is my data private?
Yes! All calculations happen in your browser. We never store or transmit any personal information.
What if my cycle is irregular?
For irregular cycles, the LMP method may be less accurate. Consult your healthcare provider for personalized dating, especially with early ultrasound.
Is this tool free?
Yes, completely free with unlimited calculations. No registration or login required.