Use this pregnancy calculator to estimate your due date, gestational age, and conception window. Enter your LMP, conception date, ultrasound dating, IVF transfer date, or a known EDD, and the pregnancy due date calculator does the rest.

Technical Notes & Limitations

• Estimates only: All pregnancy calculator results are estimates. Individual pregnancies vary significantly.
• 280-day assumption: The pregnancy due date calculator uses Naegele’s rule (280 days from LMP). Actual gestation ranges 266 to 294 days.
• Ultrasound accuracy: First-trimester ultrasound (7 to 13 weeks) is most accurate for dating.
• Cycle length matters: This pregnancy calculator assumes a 14-day luteal phase; longer or shorter cycles affect ovulation timing.
• Clinical validation needed: Always consult healthcare providers for medical decisions.
• IVF precision: IVF pregnancy calculator results use precise fertilization dates, but individual embryo development varies.

About this pregnancy calculator

This pregnancy calculator estimates your due date (EDD), gestational age (weeks + days), and trimester.

Methods supported by the pregnancy due date calculator:

• LMP + cycle length (the most common method)
• Known conception date
• IVF: day-3 or day-5 embryo transfer
• Due Date (EDD)
• Ultrasound

Use the pregnancy calculator as a guide. It does not diagnose or replace clinical care.

How to use the pregnancy calculator

• Choose your method (LMP, conception date, ultrasound, IVF transfer, or a known EDD).
• Enter the date(s) and, if using LMP, your typical cycle length.
• The pregnancy due date calculator shows your estimated due date and how far along you are today. To pinpoint your fertile window separately, try the ovulation calculator.

What your pregnancy calculator result means

• The due date marks 40 weeks from the start point used by the pregnancy calculator.
• “Full term” is a range (commonly 37 to 42 weeks); timing varies by person.
• Clinicians may adjust your date after an early ultrasound, even if the pregnancy due date calculator gave a different estimate.

Accuracy and limitations

• The pregnancy calculator is most accurate for regular cycles and when the method/date is known.
• The pregnancy due date calculator is less accurate with irregular cycles, late ovulation, recent hormonal birth control, PCOS, postpartum/breastfeeding cycles, or multiple pregnancy (twins+).
• Early ultrasound is typically more precise than any calendar-based pregnancy calculator.

Quick next steps if you’re pregnant

• Start a prenatal vitamin with 400 to 800 mcg folic acid.
• Book a prenatal visit (often around 8 to 10 weeks, or sooner as advised).
• Maintain balanced nutrition, movement, sleep, and avoid smoking and alcohol.
• Be mindful of personal-care products — some ingredients are worth avoiding during pregnancy.
• Learn what’s happening hormonally — pregnancy hormones change rapidly across all three trimesters.

Key prenatal milestones (approximate)

• 6 to 10 weeks: First prenatal visit/early ultrasound (clinic dependent).
• 10 to 13 weeks: First-trimester screening/NIPT (if chosen).
• 18 to 22 weeks: Anatomy ultrasound.
• 24 to 28 weeks: Glucose screening for gestational diabetes.
• 28 to 32 weeks: Rho(D) immune globulin if Rh-negative (as advised).
• 36 to 37 weeks: Group B strep (GBS) test.

FAQs

How is the due date calculated?

For a 28-day cycle, it’s roughly LMP + 280 days. Different cycle lengths require adjustment.

What is the difference between the gestational age and the fetal age?

Gestational age counts from LMP; fetal age is usually ~2 weeks less.

How do I enter IVF dates?

Select IVF and choose day-3 or day-5 transfer with the transfer date.

Will this work for me if I have irregular cycles?

Use as a rough guide; ask your clinician about ultrasound dating.

Can this pregnancy calculator confirm pregnancy?

No. Use a home test and confirm with your clinician.

Note: Educational information only—not medical advice. If you have severe pain, heavy bleeding, fever, signs of ectopic pregnancy (one-sided pain, shoulder pain, dizziness), or anything that worries you, seek medical care promptly.