24 weeks pregnant
This calculator finds an estimated due date and how far along you are. The worked example is a pregnancy at exactly 24 weeks.
How it works
Forty weeks is 280 days. Add 280 days to the first day of your last period for the due date. Divide the days that have passed by 7 for weeks and days. On this page the pregnancy is 168 days from the first day of the last period.
Worked example
Start at 17 December. Count 280 days ahead to reach 23 September. Count 168 days ahead to reach 3 June. 168 divided by 7 is 24 weeks. 112 days remain. A leap year shifts dates after February by one day.
Common questions
What if my cycle is not 28 days?
The 280 day rule assumes ovulation near day 14. If your cycle is much longer or shorter, your doctor may adjust the due date, often with an ultrasound. With a 35-day cycle some clinicians add 7 days, which would move 23 September to 30 September.
Does a leap year change the due date?
It can. A year with an extra day in February moves dates after that day by one. The calculator above uses the real calendar for your dates. If the span from 17 December includes a 29 February, 23 September reads one day earlier, as 22 September.
How many months is 24 weeks pregnant?
About 5.5 months. A pregnancy is 40 weeks, a little over 9 calendar months. Months are only a rough guide. At 24 weeks there are 112 days to the due date.
Which trimester is week 24?
Second trimester. The first trimester covers weeks 1 to 13, the second covers weeks 14 to 27 and the third runs from week 28 to the birth. Week 24 is week 11 of the second trimester.
Why do weeks start from the last period and not conception?
Most people know the date of their last period but not the day of conception. Counting from the last period gives everyone the same starting point. A pregnancy is about two weeks longer on paper than from conception. Counted from conception, this would be week 22, which is 154 days.