How is my due date calculated?

The most common method is using the first day of your last menstrual period (LMP) by adding 280 days (40 weeks). You can also calculate based on a known conception date or IVF transfer date.

How accurate is the due date calculation?

Due dates are estimates. Only about 5% of babies are born exactly on their due date. Most are born between 38 and 42 weeks. The calculator provides a reliable estimate based on standard medical formulas.

What is gestational age?

Gestational age is the age of the pregnancy measured in weeks, starting from the first day of your last menstrual period (LMP). It typically lasts about 40 weeks from LMP to birth.

How do I calculate due date for IVF pregnancy?

For IVF pregnancies, select the IVF transfer option and enter your transfer date along with the embryo age (day 3 or day 5). The calculator uses specialized formulas for accurate results.

What are the trimesters and how are they divided?

Pregnancy is divided into three trimesters: First trimester (weeks 1-12), Second trimester (weeks 13-27), and Third trimester (weeks 28-40+). The calculator shows your current trimester automatically.

Is this calculator free to use?

Yes, the Pregnancy Due Date Calculator on Easy Tools HQ is completely free and works directly in your browser with no registration required.

Pregnancy Due Date Calculator

Estimate due date, conception, current week, and trimester

Planning for your baby's arrival? Our Pregnancy Due Date Calculator helps you estimate your due date, current gestational age, and trimester based on your last menstrual period, a known due date, or IVF transfer date. Get instant, reliable results to help you track your pregnancy journey.

How to Use the Pregnancy Due Date Calculator

Our Pregnancy Due Date Calculator provides accurate estimates based on standard medical formulas. Here's how to use it:

Choose your calculation method – Select from Last Menstrual Period (LMP), Known Due Date (reverse), or IVF Transfer Date.
Enter your date – Depending on your method, enter your LMP date, due date, or IVF transfer date.
Adjust cycle length – For LMP method, you can adjust your average cycle length (default 28 days) for more accurate results.
Select embryo age – For IVF, choose Day 3 or Day 5 embryo transfer for the correct calculation.
View your results – The tool displays your due date, current weeks pregnant, weeks to go, trimester, progress percentage, and key milestones.
Share your results – Use the share buttons to share your due date with family and friends.
Save your calculation – Click "Save to history" to keep a record of your due date calculations.

3 Calculation Methods

LMP, Due Date, IVF transfer

Trimester Tracking

Automatic trimester detection

Key Milestones

Important pregnancy milestones

Progress Tracker

Visual progress percentage

Calculation method

Last menstrual period (LMP)

Due date (reverse)

IVF transfer date

First day of last period

Average cycle length (days)

Due date calculated by adding 280 days (40 weeks) to LMP, adjusted for cycle length.

IVF: day 3 transfer → add 266 days; day 5 → add 261 days.

Your due date & pregnancy

Estimated due date

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weeks pregnant

weeks to go

Progress to 40 weeks 0%

Trimester: First trimester

Key milestones

Recent due date calculations

Saved	LMP / method	Due date	Gestation	Action

Important Medical Disclaimer

The Pregnancy Due Date Calculator provided by Easy Tools HQ is for general informational and educational purposes only. It is not a medical device and should not be used as a substitute for professional medical advice, diagnosis, or treatment.

Important medical notice: Due dates are estimates only. Only 5% of babies are born exactly on their due date. Actual delivery dates can vary based on many factors including cycle irregularity, ovulation timing, and individual medical circumstances. IVF calculations are estimates based on standard transfer protocols.

Always consult your healthcare provider – obstetrician, midwife, or fertility specialist – for accurate dating, prenatal care, and medical guidance. Every pregnancy is unique, and only qualified medical professionals can provide personalized care.

If you think you may be pregnant, have pregnancy complications, or experience any concerning symptoms, please contact your healthcare provider immediately.

Last Updated: March 2026

Estimates only • Consult your doctor