Pregnancy Date Due Calculator
Calculate Your Due Date
Choose your calculation method below
Enter the first day of your last menstrual period. Most accurate for regular 28-day cycles.
Please select a date to continue.
Your due date will be calculated as 280 days (40 weeks) from this date
Adjusts ovulation timing for longer or shorter cycles
Know when you conceived? Enter that date and we'll calculate forward 266 days (38 weeks).
Please select a conception date.
Due date = conception date + 266 days
For IVF pregnancies, enter your embryo transfer date and the age of the embryo at transfer.
Please select your transfer date.
Most transfers use Day 5 blastocysts
Weeks Along
—
as of today
Trimester
—
current stage
Conception Date
—
estimated
Days Remaining
—
until your due date
📍 Your Pregnancy Milestones
First Trimester ends
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Week 1 – 12 · Organ formation & early development
Second Trimester ends
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Week 13 – 26 · Growth & movement begins
Third Trimester ends
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Week 27 – 40 · Final growth & preparation for birth
🌸 Pregnancy Progress
0%Remember — only about 4% of babies are born on their exact due date. Your due date is the midpoint of a normal delivery window of 37–42 weeks.
How Is My Due Date Calculated?
Last Menstrual Period (LMP): The most widely used method. Your due date is calculated as 280 days (40 weeks) from the first day of your last period. If your cycle differs from 28 days, the calculator adjusts ovulation timing accordingly.
Conception Date: If you know when you conceived — through ovulation tracking, BBT charting, or ovulation tests — we add 266 days (38 weeks) directly to that date for a more precise result.
IVF Transfer Date: For IVF pregnancies, gestational age is calculated from the transfer date adjusted for the embryo's age. A Day 5 blastocyst transfer adds 261 days; Day 3 embryos add 263 days.
Frequently Asked Questions
Due dates are estimates, not guarantees. Only about 4% of babies are born on their exact due date. A full-term pregnancy is anywhere between 37 and 42 weeks — so a window of several weeks either side is perfectly normal.
An early ultrasound (before 12 weeks) is often more accurate than LMP-based calculations because it directly measures the embryo. If your ultrasound date differs by more than 7 days, your doctor may adjust your official due date accordingly.
The first trimester covers weeks 1–12, the second covers weeks 13–26, and the third covers weeks 27–40. These are approximate — some practitioners split them slightly differently.
Yes — use the Conception Date or IVF tab if you have that information. Otherwise, an early ultrasound scan is the most reliable way for your doctor to estimate gestational age without a known LMP.
The dates calculated are based on a singleton pregnancy. Twin and multiple pregnancies typically have earlier delivery dates — your OB or midwife will give you a more tailored estimate based on your scans.
This tool is for informational purposes only and does not constitute medical advice. Always consult your healthcare provider or midwife for personalised guidance during pregnancy.