Pregnancy Due Date Calculator

Calculate your expected delivery date (EDD) using one of three methods: Last Menstrual Period (LMP), Conception Date, or IVF Transfer Date.

Calculation Method:

First Day of Last Menstrual Period:

Cycle Length (optional):

days

Current Date:

Trimester	Weeks	Key Developments
First Trimester	1-12	Organ development, morning sickness, fatigue, increased urination
Second Trimester	13-26	Baby movement, gender determination, improved energy, growing belly
Third Trimester	27-40	Rapid baby growth, shortness of breath, Braxton Hicks contractions, nesting instinct

Important Facts About EDD
EDD is an estimate, not a guarantee. Only about 4% of babies are born on their actual due date. EDD can be calculated in multiple ways: Last Menstrual Period (LMP), Conception Date, IVF Transfer Date, or Early Ultrasound Measurements. LMP Method assumes a 28-day cycle and counts 40 weeks (280 days) from the first day of the last menstrual period. Conception Date calculation adds 266 days (about 38 weeks) to the date of conception. IVF offers precise due date estimation: Day 3 embryo transfer (add 263 days) or Day 5 embryo transfer (add 261 days). Early ultrasound scans (especially before 12 weeks) provide highly accurate estimation of gestational age and EDD. Gestational age counts from the first day of the last menstrual period, not the day of conception. A full-term pregnancy can range from 37 to 42 weeks from the LMP. Individual factors like cycle irregularity or multiple pregnancies can shift the actual delivery date. If unsure about dates, it’s best to consult a healthcare provider who may use ultrasound scans to confirm the EDD.

Important Facts About EDD

EDD is an estimate, not a guarantee. Only about 4% of babies are born on their actual due date.
EDD can be calculated in multiple ways: Last Menstrual Period (LMP), Conception Date, IVF Transfer Date, or Early Ultrasound Measurements.
LMP Method assumes a 28-day cycle and counts 40 weeks (280 days) from the first day of the last menstrual period.
Conception Date calculation adds 266 days (about 38 weeks) to the date of conception.
IVF offers precise due date estimation: Day 3 embryo transfer (add 263 days) or Day 5 embryo transfer (add 261 days).
Early ultrasound scans (especially before 12 weeks) provide highly accurate estimation of gestational age and EDD.
Gestational age counts from the first day of the last menstrual period, not the day of conception.
A full-term pregnancy can range from 37 to 42 weeks from the LMP.
Individual factors like cycle irregularity or multiple pregnancies can shift the actual delivery date.
If unsure about dates, it’s best to consult a healthcare provider who may use ultrasound scans to confirm the EDD.

Factor	Description
Irregular Menstrual Cycles	If a woman’s periods are not regular, it can be difficult to pinpoint the exact date of ovulation, making it harder to calculate the due date accurately.
Genetic Predisposition	There’s a genetic component to pregnancy length. If a woman or her family members have had post-term births (after 42 weeks), she may be more likely to have a similar experience.
Ultrasound Accuracy	While ultrasounds can provide a good estimation of gestational age, they are not always perfectly accurate. Early ultrasounds (6-9 weeks) are generally more accurate for due date calculations than those done later in pregnancy.
Maternal Height	Studies suggest that women who are shorter (under 5’3″) may have babies who arrive earlier, while women who are taller (5’6″ or more) may have babies who stay in longer.
Ethnicity	Some research indicates that ethnicity can also influence the duration of pregnancy.
Placenta Issues	Problems with the placenta, like placenta previa, can increase the risk of preterm delivery.
Maternal Health	Conditions like gestational diabetes or high blood pressure can also affect the timing of delivery.
Weight Gain	Excessive weight gain during pregnancy can be associated with later deliveries.
Fetal Development	Some babies simply develop faster in utero, potentially leading to earlier births.
Multiple Gestations	Women carrying twins or multiples are more likely to deliver earlier than women carrying a single fetus.

Fun Facts
The idea of a 40-week pregnancy was established by German obstetrician Franz Naegele in the early 1800s. The most common birthday in the United States is September 9th, suggesting that many babies are conceived during the winter holidays. First-time mothers are more likely to deliver after their due date than women who have had previous pregnancies. A typical healthy pregnancy can vary naturally by up to five weeks (37-42 weeks). Male babies tend to stay in the womb slightly longer than female babies on average. The length of pregnancy can vary by season, with some studies suggesting winter pregnancies may be slightly longer. Only about 5% of babies are born exactly on their due date, with 80% being born within two weeks before or after. The full moon does not statistically increase the likelihood of going into labor, despite the popular myth. Ancient Egyptians used pregnancy tests where a woman would urinate on barley and wheat seeds – faster growth indicated pregnancy. The Guinness World Record for the longest pregnancy belongs to Beulah Hunter, who carried her baby for 375 days (1.5 months beyond the average).

Fun Facts

The idea of a 40-week pregnancy was established by German obstetrician Franz Naegele in the early 1800s.
The most common birthday in the United States is September 9th, suggesting that many babies are conceived during the winter holidays.
First-time mothers are more likely to deliver after their due date than women who have had previous pregnancies.
A typical healthy pregnancy can vary naturally by up to five weeks (37-42 weeks).
Male babies tend to stay in the womb slightly longer than female babies on average.
The length of pregnancy can vary by season, with some studies suggesting winter pregnancies may be slightly longer.
Only about 5% of babies are born exactly on their due date, with 80% being born within two weeks before or after.
The full moon does not statistically increase the likelihood of going into labor, despite the popular myth.
Ancient Egyptians used pregnancy tests where a woman would urinate on barley and wheat seeds – faster growth indicated pregnancy.
The Guinness World Record for the longest pregnancy belongs to Beulah Hunter, who carried her baby for 375 days (1.5 months beyond the average).