Pregnancy Calculator

Free online pregnancy calculator to calculate your due date, current pregnancy week, trimester information, and important pregnancy milestones. Track your pregnancy journey with accurate calculations based on your last menstrual period or conception date.

Calculate Your Pregnancy Details

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Pregnancy Timeline & Milestones

Week Trimester Baby Size Key Development
Week 4 1st Trimester Poppy seed Implantation occurs
Week 8 1st Trimester Raspberry Heart starts beating
Week 12 1st Trimester Lime End of first trimester
Week 16 2nd Trimester Avocado Gender can be determined
Week 20 2nd Trimester Banana Anatomy scan, halfway point
Week 24 2nd Trimester Corn Viability milestone
Week 28 3rd Trimester Eggplant Third trimester begins
Week 32 3rd Trimester Squash Rapid brain development
Week 36 3rd Trimester Papaya Considered full-term soon
Week 40 Full Term Watermelon Due date arrives!

Trimester Information

Trimester Weeks Months Key Features
First Trimester 1-12 weeks 1-3 months Morning sickness, fatigue, organ formation
Second Trimester 13-27 weeks 4-6 months Energy returns, baby movements, anatomy scan
Third Trimester 28-40 weeks 7-9 months Rapid growth, preparation for birth
Pregnancy Calculation Guidelines
Full Term Pregnancy 40 weeks (280 days) from LMP
Conception to Birth 38 weeks (266 days)
Early Term 37-38 weeks
Full Term 39-40 weeks
Late Term 41 weeks
Post Term 42+ weeks

About Pregnancy Calculation

Pregnancy calculations are based on the first day of your last menstrual period (LMP) using Naegele's rule. This method adds 280 days (40 weeks) to the LMP to estimate the due date, which is the standard used by healthcare providers worldwide.

Calculation Methods

  • Last Menstrual Period (LMP): Most common method, adds 280 days to LMP
  • Conception Date: Adds 266 days to known conception date
  • Due Date: Works backward from known due date
  • Ultrasound Dating: Most accurate, especially in early pregnancy

Pregnancy Trimesters

  • First Trimester (1-12 weeks): Organ formation, morning sickness common
  • Second Trimester (13-27 weeks): Often called the "golden period"
  • Third Trimester (28-40 weeks): Rapid growth and preparation for birth

Important Considerations

  • Only 5% of babies are born on their exact due date
  • Normal delivery can occur 2 weeks before or after due date
  • Cycle length variations can affect accuracy
  • Ultrasound dating is more accurate than LMP dating
  • Always consult healthcare providers for medical advice

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 based on Naegele's rule, the standard method used by healthcare providers.

How long is a pregnancy?

A full-term pregnancy lasts approximately 40 weeks (280 days) from the last menstrual period, or 38 weeks from conception. This equals about 9 months and 1 week.

What are the pregnancy trimesters?

Pregnancy is divided into three trimesters: First trimester (weeks 1-12), Second trimester (weeks 13-27), and Third trimester (weeks 28-40).

How accurate are pregnancy calculators?

Pregnancy calculators provide estimates based on average cycle lengths. Ultrasound dating is more accurate, especially when done in the first trimester. Always consult your healthcare provider for precise dating.

See Also