Enter your last menstrual period date, conception date, IVF transfer date, or ultrasound details to calculate your estimated due date (EDD). The Due Date Calculator also shows your current gestational age, trimester, and weeks remaining so you can track your pregnancy milestones at a glance.
Estimated Due Date
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Current Gestational Age
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Current Trimester
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Weeks Remaining
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Estimated Conception Date
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An estimated due date (EDD) is a calculated prediction of when your baby is expected to be born, typically 40 weeks from the first day of your last menstrual period. It's important to remember it's only an estimate — only about 4–5% of babies are born exactly on their due date, with most arriving within two weeks before or after.
The most common method uses Naegele's Rule: add 280 days (40 weeks) to the first day of your last menstrual period (LMP), adjusted for your average cycle length. If your cycle is longer or shorter than 28 days, the ovulation date — and therefore the due date — shifts accordingly.
Due date estimates are most accurate when based on a first-trimester ultrasound, which can be accurate to within 5–7 days. LMP-based estimates are accurate to within 2 weeks for most women with regular cycles. Factors like irregular periods, late ovulation, or varying cycle lengths can all affect accuracy.
Yes, your due date can change. A healthcare provider may adjust your EDD based on ultrasound measurements, especially in the first trimester. If the ultrasound date significantly differs from the LMP-based date, the ultrasound estimate is generally considered more reliable.
For a 3-day IVF embryo transfer, your due date is calculated as 263 days (38 weeks minus 3 days) from the transfer date — this accounts for the embryo already being 3 days old at transfer. For a 5-day transfer (blastocyst), add 261 days (38 weeks minus 5 days) from the transfer date.
If you already know your due date from a healthcare provider, you can use a reverse due date calculation. Simply count back 280 days from your due date to estimate your LMP, or use this tool to track milestones, trimester transitions, and key pregnancy dates.
Very few women — only about 4–5% — give birth exactly on their due date. The majority of babies (about 80%) are born within two weeks before or after the EDD. A full-term pregnancy is generally considered 39–40 weeks, though anywhere from 37 to 42 weeks is normal.
Most home pregnancy tests can detect the hCG hormone as early as 10–14 days after conception, or around the time of a missed period. For the most reliable results, wait until the first day of your missed period. Blood tests at a clinic can detect pregnancy even earlier, around 6–8 days after ovulation.