Wondering when your baby will arrive? Our free pregnancy due date calculator gives you an accurate estimate of your baby’s birth date. Simply enter your last period date or conception date to find out.
Pregnancy Due Date Calculator
Calculate your estimated due date based on your last menstrual period or conception date.
How it works:
- If using last menstrual period: Your due date is calculated as 280 days (40 weeks) from the first day of your last period.
- If using conception date: Your due date is calculated as 266 days (38 weeks) from conception.
- Only about 5% of babies are born exactly on their due date. Most are born within a week before or after.
How to Use This Due Date Calculator
Our calculator offers two simple ways to find your due date:
- Last Menstrual Period (LMP): Select the first day of your last period – this is what most doctors use.
- Conception Date: If you know when you conceived (through tracking or fertility treatment), this can give you a more precise estimate.
After entering your date, you’ll see:
- Your baby’s estimated due date
- Your current pregnancy week
- Which trimester you’re in
How Are Due Dates Calculated?
Most healthcare providers use Naegele’s rule to calculate due dates:
- From LMP: Add 280 days (40 weeks) to the first day of your last period
- From conception: Add 266 days (38 weeks) to your conception date
This calculation works best for women with regular 28-day cycles with ovulation on day 14.
Why Knowing Your Due Date Is Important
Your estimated due date helps you:
- Track your baby’s development week by week
- Schedule prenatal appointments at the right times
- Plan maternity leave and prepare your home
- Know what pregnancy symptoms to expect when
- Monitor for any signs of early or late labor
When to See Your Doctor After Finding Your Due Date
While this calculator gives you a good estimate, your doctor will:
- Confirm your due date at your first prenatal visit
- May adjust it based on ultrasound measurements
- Track your baby’s growth throughout pregnancy
Always consult with your healthcare provider for the most accurate pregnancy dating.
Next Steps After Calculating Your Due Date
Now that you know when to expect your baby:
- Book your first prenatal checkup
- Start taking prenatal vitamins
- Plan your maternity leave timing
- Create a pregnancy timeline
- Consider when to announce your pregnancy
Frequently Asked Questions About Due Dates
Will my baby be born exactly on the due date? Probably not. Only 5% of babies arrive on their exact due date. Most babies come between 37 and 42 weeks of pregnancy.
My periods are irregular. Will this calculator work? This calculator works best for regular cycles. If yours are irregular, an early ultrasound will give you a more accurate due date.
Can my due date change during pregnancy? Yes. Your doctor may adjust your due date based on ultrasound measurements, especially in the first trimester.
What if I go past my due date? If you go beyond 41 weeks, your doctor will monitor you closely and may recommend induction to prevent complications.
How accurate is the due date calculator? This calculator provides an estimate based on standard pregnancy timing. Your actual delivery date may vary by 1-2 weeks in either direction.
Note: This calculator provides an estimate only. Please consult with your healthcare provider for the most accurate information about your pregnancy.
