Due Date Calculator

Our comprehensive due date calculator offers three accurate methods to determine your pregnancy due date and track your baby's development:

1. Choose your preferred calculation method (LMP, conception, or ultrasound)
2. Enter the required dates and information
3. Click "Calculate Due Date" to get comprehensive pregnancy information
4. Review your personalized timeline, milestones, and recommendations

The calculator provides detailed week-by-week information including baby size comparisons, important milestones, trimester breakdowns, and health recommendations tailored to your current stage of pregnancy.

Last Menstrual Period (LMP)

The most common method using Naegele's rule. Add 280 days (40 weeks) to the first day of your last menstrual period. This assumes a 28-day cycle with ovulation on day 14.

• Most widely used by healthcare providers
• Based on average 28-day menstrual cycle
• Accounts for typical ovulation timing
• Adjustable for different cycle lengths

Conception Date

If you know the exact conception date (through fertility tracking, IVF, etc.), this method adds 266 days (38 weeks) to calculate the due date.

• Most accurate when conception date is known
• Common for assisted reproductive technologies
• Based on actual fertilization timing
• Eliminates cycle length variations

Ultrasound Dating

Uses measurements from an ultrasound scan to determine gestational age and calculate the due date. Most accurate when performed in the first trimester.

• Based on fetal measurements
• Most accurate in early pregnancy (6-12 weeks)
• Can adjust for irregular cycles
• Provides visual confirmation of development

Pregnancy is divided into three trimesters, each lasting approximately 13 weeks. Each trimester brings unique developments, symptoms, and milestones.

First Trimester (Weeks 1-12)

• Key Developments: Major organs form, heartbeat begins
• Common Symptoms: Morning sickness, fatigue, breast tenderness
• Important Milestones: Neural tube formation, limb development
• Prenatal Care: Confirm pregnancy, begin prenatal vitamins

Second Trimester (Weeks 13-26)

• Key Developments: Gender determination, movement begins
• Common Symptoms: Energy returns, visible baby bump
• Important Milestones: Anatomy scan, quickening
• Prenatal Care: Regular checkups, genetic screening

Third Trimester (Weeks 27-40)

• Key Developments: Rapid growth, lung maturation
• Common Symptoms: Back pain, frequent urination, nesting
• Important Milestones: Viability, full term
• Prenatal Care: Birth planning, increased monitoring

Track your baby's incredible development journey with week-by-week milestones and size comparisons to familiar objects.

Early Development (Weeks 4-12)

• Week 4: Size of poppy seed - implantation occurs
• Week 6: Size of lentil - heartbeat begins
• Week 8: Size of kidney bean - major organs forming
• Week 12: Size of plum - first trimester complete

Rapid Growth (Weeks 13-26)

• Week 16: Size of avocado - gender can be determined
• Week 20: Size of banana - anatomy scan week
• Week 24: Size of corn - viability milestone
• Week 26: Eyes begin to open

Final Preparation (Weeks 27-40)

• Week 28: Size of eggplant - third trimester begins
• Week 32: Size of coconut - rapid weight gain
• Week 36: Size of cantaloupe - approaching full term
• Week 40: Size of watermelon - ready for birth

While due date calculators provide valuable estimates, it's important to understand their limitations and the natural variation in pregnancy length.

Due Date Accuracy

• Only 5% of babies are born on their exact due date
• Most babies (90%) are born within 2 weeks of the due date
• Full term is considered 37-42 weeks gestation
• First pregnancies often go longer than subsequent ones

Factors Affecting Due Date

• Cycle Length: Longer cycles may mean later ovulation
• Maternal Age: Can influence pregnancy duration
• Previous Pregnancies: May affect timing of subsequent births
• Multiple Babies: Twins/multiples typically born earlier