Pregnancy Calculator: Calculate Your Due Date Accurately
Use our medically accurate Pregnancy Calculator to find your estimated due date, current trimester, and baby’s size. Calculate by LMP, IVF, or ultrasound!
Select your love date and click the button
How to Work This Tool
Select your calculation method—such as your last menstrual period (LMP), conception date, IVF transfer, or ultrasound—and enter your specific dates. Click calculate to instantly reveal your estimated due date, pregnancy progress countdown, and your baby’s current developmental milestones.
How We Calculate Your Estimated Due Date (EDD)
Our calculator uses Naegele’s Rule, which is the exact, standard formula used by healthcare providers and obstetricians worldwide to determine a pregnancy due date.
For a standard 28-day menstrual cycle, the formula calculates the due date by adding exactly 280 days (or 40 weeks) to the first day of your Last Menstrual Period (LMP).
The standard formula is:
- Step 1: Identify the first day of your Last Menstrual Period (LMP).
- Step 2: Add 7 days to that date.
- Step 3: Subtract 3 months.
- Step 4: Add 1 year (if necessary).
- (Alternatively: LMP Date + 280 Days = Estimated Due Date)
If you know your exact conception date or underwent IVF (In Vitro Fertilization), our tool automatically adjusts this formula. For IVF, it calculates based on your embryo transfer date and whether you transferred a Day-3 or Day-5 embryo, ensuring maximum accuracy for your unique pregnancy journey.
Frequently Asked Questions
Our calculator is highly accurate and uses the exact same math as your doctor. However, it is important to remember that an estimated due date is just an estimate. Only about 5% of babies are born on their exact due date, while most arrive safely within the full-term window of 37 to 42 weeks.
es! If you have irregular cycles, calculating by your Last Menstrual Period (LMP) might not be accurate. Instead, select the “Ultrasound Scan” or “Conception Date” option from the calculator dropdown for a highly precise result based on your baby’s actual physical development.
Unlike a natural pregnancy where conception dates can be slightly ambiguous, IVF provides exact dates. Our calculator allows you to input your exact transfer date and select the age of your embryo (Day 3 or Day 5 Blastocyst). The tool then adds either 263 days (for a Day 3 embryo) or 261 days (for a Day 5 embryo) to find your exact due date.
