Pregnancy Due Date Calculator
When will you meet your baby? Find your estimated due date and exactly how far along you are. Use your last period, conception date, IVF transfer, or a recent ultrasound.
How Your Due Date Is Calculated
Most due dates use Naegele’s rule: add 280 days (40 weeks) to the first day of your last menstrual period. Because this assumes a 28-day cycle with ovulation on day 14, we adjust if your cycle runs longer or shorter.
- Last period: due date = first day of last period + 280 days, adjusted for cycle length.
- Conception date: due date = conception + 266 days.
- IVF transfer: due date = transfer date + 261 days (day-5 blastocyst) or + 263 days (day-3 embryo).
- Ultrasound: we project forward from the gestational age measured at your scan, which is the most accurate early dating method.
Your due date is a helpful estimate, not a deadline. Your Garden OB/GYN provider will confirm and may fine-tune it at your first prenatal ultrasound.
Common Questions
How is my due date calculated?
The most common method (Naegele’s rule) adds 280 days, about 40 weeks, to the first day of your last menstrual period, assuming a 28-day cycle. Our calculator also lets you use your conception date, IVF transfer date, or an ultrasound, which can be more precise.
How accurate is a due date?
A due date is an estimate. Only about 1 in 20 babies are born on their exact due date, and most arrive in the two weeks before or after. A first-trimester ultrasound is the most accurate way to date a pregnancy, and your provider may adjust your due date based on it.
What if my cycle is not 28 days?
Use the cycle-length slider in the last-period option. If your cycle is longer or shorter than 28 days, we adjust the estimate accordingly, since ovulation (and conception) shifts with cycle length.
How many weeks pregnant am I?
Pregnancy is counted in weeks from the first day of your last period, not from conception. Enter your details above to see how far along you are in weeks and days, plus your current trimester.
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