- NextGenTools

Pregnancy Calculator

Estimate key dates in your pregnancy including due date, conception date, and pregnancy milestones.

First Day of Last Menstrual Period:

Average Cycle Length (days):

Estimated Due Date:

Average Cycle Length (days):

Ultrasound Date:

Gestational Age at Ultrasound (weeks + days):

weeks days

Pregnancy Results

Due Date: –

Conception Date: –

End of First Trimester (12 weeks): –

End of Second Trimester (27 weeks): –

Current Gestational Age: –

Days Remaining Until Due Date: –

Pregnancy Timeline

Pregnancy Calculator: Track Your Pregnancy Journey

Our pregnancy calculator helps expectant parents estimate important dates throughout pregnancy. Whether you’re trying to conceive or already pregnant, this tool provides valuable information about your pregnancy timeline.

How Pregnancy Dating Works

Pregnancy typically lasts about 40 weeks from the first day of your last menstrual period (LMP). This equals 38 weeks from conception. Healthcare providers use these standard calculations:

Last Menstrual Period (LMP) Method: Due date = LMP + 280 days (40 weeks)
Conception Date Method: Due date = Conception date + 266 days (38 weeks)
Ultrasound Dating: Most accurate in first trimester, measures fetal development

Key Pregnancy Milestones

First Trimester (Weeks 1-12): Embryonic development, organ formation
Second Trimester (Weeks 13-27): Fetal growth, movement felt
Third Trimester (Weeks 28-40): Rapid weight gain, lung maturation

Using the Pregnancy Calculator

Our calculator offers three methods to estimate your due date:

Last Period Calculation: Enter the first day of your last menstrual period
Conception Date Calculation: If you know your conception date
Ultrasound Dating: Enter ultrasound date and gestational age

Factors That Affect Due Date Accuracy

Irregular cycles: If your cycle isn’t 28 days, adjust the cycle length
Early ultrasound: First trimester ultrasounds are most accurate
IVF pregnancies: Use embryo transfer date for most accurate dating

Frequently Asked Questions

Q: How accurate are due date calculators?
A: Only about 5% of women deliver on their exact due date. Most deliver within 2 weeks before or after.

Q: Can my due date change?
A: Yes, especially if early ultrasound measurements differ significantly from LMP-based estimates.

Q: What if I don’t know my last period date?
A: An early ultrasound can provide the most accurate dating in this case.

Q: Why is pregnancy calculated from last period?
A: This standard provides a consistent starting point since conception date is often unknown.

Remember that every pregnancy is unique. Use our calculator as a guide, but always consult with your healthcare provider for personalized medical advice. Tracking your pregnancy milestones helps you prepare for each stage and anticipate your baby’s arrival.