⚠️ Medical Disclaimer: These tools are for educational purposes only and are not medical advice. Please consult your pediatrician or healthcare provider for any health concerns.
Free Tool

Pregnancy Due Date Calculator

Find your baby's estimated due date, current pregnancy week and countdown to delivery. Instantly and for free.

100% Free No Login Works on Mobile Data Stays Private

In the US, due date calculation kicks off the whole pregnancy timeline: when do I tell work, when does my insurance need updates, when can I take the maternity leave my employer offers (or doesnt). This calculator uses the same medical formula your OB-GYN will use (Naegele rule, LMP plus 280 days). We show conception window, key prenatal appointment timing, and the AAP-recommended screening windows so you can plan ahead.

📅 Pregnancy Due Date Calculator

Enter your LMP date to find your baby's due date and current pregnancy week

Estimated Due Date
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Current
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Trimester
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How is the due date calculated?

Your due date is estimated by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP). This is known as Naegele's rule and is the most common method used by doctors worldwide.

This calculator provides an estimate only. Please consult your doctor or gynecologist for accurate medical advice and confirmation of your pregnancy timeline.

Step-by-Step Guide

How to use this tool

Uses Naegele's Rule. The standard medical formula worldwide. Takes 30 seconds.

  1. 1
    Enter your Last Menstrual Period (LMP) date

    The first day your last period started. Not when it ended. Check your period app if unsure.

  2. 2
    Enter your average cycle length

    Default is 28 days. Update if your cycle is shorter or longer for a more accurate result.

  3. 3
    Click Calculate Due Date

    Your due date, current week, trimester, and countdown appear instantly.

  4. 4
    Save or screenshot your results

    Take a screenshot to share with your doctor. Return anytime to check your current week.

💡 Did your doctor give a different date?

Your first ultrasound can shift the due date by a few days. This is normal. Ultrasound dating is more accurate if they differ by more than 5 days.

⚠️ Only 5% of babies arrive on their due date

Your due date is an estimate. Babies born between 37 and 42 weeks are full-term. Do not stress if your date changes slightly.

FAQ

Frequently Asked Questions

Uses Naegele's Rule. The standard medical method worldwide. Accurate to within a few days for regular cycles. Your first ultrasound (8-12 weeks) will confirm or refine the date.
Check your period tracking app (Flo, Clue). Your doctor can calculate your due date from an early ultrasound scan.
Yes. Our calculator accounts for this. Women with shorter cycles ovulate earlier, those with longer cycles ovulate later. Enter your actual cycle length.
For IVF, the due date is based on embryo transfer date. Day 5 blastocyst: add 261 days. Day 3 transfer: add 263 days.
Healthcare in USA

How pregnancy due date estimation care actually works in the United States

Pediatric care in America has too many decision points. Most parents do not realize this until midnight on a Tuesday. Your pediatrician handles routine stuff. After hours though, you have options to sort through. Nurse triage line that comes with your pediatric practice, free. Telehealth like Teladoc or Amwell, usually a small copay through insurance. Urgent care clinics, the CVS MinuteClinic and Walgreens Healthcare type places, around $100 to $150 cash. ER for actual emergencies, anywhere from $500 to $3000 even with insurance. Choice depends on baby age, severity of what is going on, and your insurance situation. Under 3 months with any fever (100.4 Fahrenheit, 38 Celsius), skip the decision tree completely. Go straight to ER. AAP is firm on that one.

📞 Emergency contacts in the United States

For emergencies in the US: call 911. For non-emergency advice, call your pediatrician or the Poison Control Center at 1-800-222-1222 if you suspect a medication issue. Telehealth services like Teladoc, Amwell, and MDLive offer 24/7 pediatric consultations covered by most insurance plans.

Context for American families

What American moms actually deal with

American parents get conflicting advice from every direction. Wellness industry says lavender oil for everything. Some of those oils are actually unsafe for babies under 2 years old. Online mom forums swing from "every fever is fine, just wait it out" to "rush to the ER right now." Pediatricians want measured responses based on evidence. Insurance companies want you to call the nurse line first. None of these voices is entirely wrong. Just incomplete. AAP guidance is consistent and worth trusting more than Instagram momfluencers. For babies over 3 months, watchful waiting with Tylenol or Motrin and good hydration is fine for 24 to 48 hours unless something concerning develops. Under 3 months, any fever is an ER visit. No exceptions, no waiting it out.

More FAQs for USA

American-specific questions

FMLA gives eligible employees up to 12 weeks of unpaid, job-protected leave around childbirth. Your due date is the anchor for planning when leave starts and ends. To qualify for FMLA you must have worked for your employer at least 12 months and 1250 hours in the prior 12 months. State-level paid leave (in California, New York, New Jersey, others) may offer additional protections. Check your states Department of Labor website.
Pregnancy Medicaid in most states covers from conception through 60 days postpartum, with some states extending to 12 months. Your due date is what your state agency will use for coverage windows. Apply through your state Medicaid agency as soon as you confirm pregnancy. WIC eligibility also runs through due date timing.
The American Academy of Pediatrics and ACOG (American College of Obstetricians and Gynecologists) recommend specific screening tests at specific gestational ages because thats when results are most reliable. NIPT testing is most accurate at 10+ weeks, anatomy scan at 18-22 weeks, glucose tolerance test at 24-28 weeks, Group B strep test at 36-37 weeks. Your due date sets these windows.
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