The due date calculator estimates the date a baby is due to be born by using the date of the first day of the woman’s last period and her average menstrual cycle length to calculate the estimated date of the baby’s birth.
What is a delivery date calculator?
If a woman is pregnant, then a due date calculator will estimate the date when her baby is likely to be born. It asks her for the date she started her last period and her average cycle length and uses this information to estimate the day she ovulated. Since she can only become pregnant within 24 hours of ovulation due to the short lifespan of the egg if not fertilised by a sperm, the day of ovulation is an excellent predictor of the day conception took place, and from there, the calculator can approximate the likely date her baby is due.
How to use the due date calculator?
- Enter the date your last period started on the calendar.
- Enter your average cycle length from the drop down list.
- Then clicks calculate.
What do the results mean?
When you clicks “calculate” you’ll see a date given in the results box. This is just an estimate, as everyone knows that not all babies arrive on their predicted due date!
How accurate is the due date calculator?
The Due Date Calculator can only give women an estimate of their baby’s due date. It is advised to always see a healthcare provider for more information about a pregnancy.
How is my due date calculated?
Your due date is calculated by adding 280 days (40 weeks) to the first day of your last menstrual period (assuming a 28-day cycle).
Note that your menstrual period and ovulation are counted as the first two weeks of pregnancy. If you deliver on your due date, your baby is actually only 38 weeks old, not 40 because we calculate from your LMP not the date of fertilization.
Is due date calculation effective?
Please remember that your due date is only an estimate. Every pregnancy is unique and your baby will come when it’s ready. Be sure to talk to your healthcare provider about your due date.
On average only 5% of births take place exactly on the estimated due date. Most are born within a week either side of the estimated due date. A normal pregnancy can last anywhere between 38 and 42 weeks.