Due Date & Week by Week Tracker
✓ 3 Calculation Methods - LMP, Conception, Ultrasound
✓ Week-by-Week Baby Size - 40 weeks of development
✓ Important Milestones - Heartbeat, kicks, scans
✓ Trimester Info - Symptoms & development stages
Normal range: 21-35 days (default: 28)
💡 Note:
Only 5% of babies arrive exactly on their due date. Most arrive within 2 weeks before or after.
Enter your details to calculate
A Pregnancy Calculator (Due Date Calculator) estimates your baby's due date and tracks your pregnancy week by week. It calculates based on your Last Menstrual Period (LMP), conception date, or ultrasound scan results.
Our calculator provides 3 calculation methods, tracks 40 weeks of baby development, shows baby size comparisons (poppy seed to watermelon), identifies your current trimester, and highlights important pregnancy milestones like first heartbeat, gender reveal, and viability dates.
Most Common Method: Calculates due date from the first day of your last period.
Formula:
Due Date = LMP + 280 days (40 weeks)
Adjusted for cycle length if ≠ 28 days
✓ Pros: Easy to remember, standard method
⚠️ Cons: Assumes 28-day cycle, ovulation on day 14
Most Accurate: If you know the exact date of conception or ovulation.
Formula:
Due Date = Conception + 266 days (38 weeks)
From ovulation to birth
✓ Pros: Most precise if date is known
⚠️ Cons: Difficult to know exact conception date
Doctor's Standard: Based on baby's measurements from ultrasound scan.
Formula:
Due Date = Ultrasound Date + (280 - Gestational Age)
Uses baby's actual size
✓ Pros: Most reliable, based on fetal size
⚠️ Cons: Requires ultrasound scan
Week 1-12 (Months 1-3)
Development:
Common Symptoms:
Week 13-26 (Months 4-6)
Development:
Common Symptoms:
Week 27-40 (Months 7-9)
Development:
Common Symptoms:
WEEK 5-6
Heartbeat Detected
Baby's heart starts beating, visible on ultrasound
WEEK 8
Baby Starts Moving
First movements (too tiny to feel yet)
WEEK 12
First Ultrasound (Dating Scan)
Confirm due date, check development
WEEK 16-20
Gender Determination
Baby's gender can be seen on ultrasound
WEEK 18-20
First Kicks Felt!
Quickening - you feel baby's movements
WEEK 20
Anatomy Scan
Detailed ultrasound checking all organs
WEEK 24
Viability Milestone
Baby could survive if born premature
WEEK 28
Third Trimester Begins
Final stretch of pregnancy
WEEK 32-36
Baby Drops (Lightening)
Baby moves down into pelvis
WEEK 36+
Weekly Doctor Visits
More frequent checkups begin
WEEK 37
Full Term!
Baby is considered full term
WEEK 40
Due Date!
Estimated delivery date
| Month | Weeks | Trimester | Key Milestones |
|---|---|---|---|
| Month 1 | 1-4 | First | Conception, implantation |
| Month 2 | 5-8 | First | Heartbeat starts, morning sickness begins |
| Month 3 | 9-13 | First | Major organs formed, first ultrasound |
| Month 4 | 14-17 | Second | Energy returns, baby's sex forming |
| Month 5 | 18-21 | Second | Feel baby kicks, anatomy scan |
| Month 6 | 22-26 | Second | Baby's eyes open, viability reached |
| Month 7 | 27-30 | Third | Third trimester begins, baby can hear |
| Month 8 | 31-35 | Third | Baby grows rapidly, weekly checkups start |
| Month 9 | 36-40 | Third | Full term at 37 weeks, ready for birth! |
Pregnancy due date calculators are approximately 80% accurate within 2 weeks of the predicted date. Only about 5% of babies arrive exactly on their due date.
Accuracy by Method:
💡 Tip: Most babies (90%) are born between 37-42 weeks. This is considered "full term" and perfectly normal.
A full-term pregnancy is 40 weeks (280 days) from the first day of your last menstrual period, or 38 weeks (266 days) from conception.
Pregnancy Duration Classifications:
If you don't remember your last menstrual period or conception date, an ultrasound scan is the best method to determine your due date.
Solutions:
Important: Your doctor will use ultrasound measurements as the primary method if LMP is uncertain. The dating ultrasound between weeks 8-12 is considered the gold standard.