Pregnancy Due Date Ranges

This table attempts to estimate your probability of going into labor on different individual days based on your estimated due date. If you don't know your due date, or just want a handy daily page to tell you where you're at, use the pregnancy calendar.

It's based on the idea that the average pregnancy lasts 40 weeks with a standard deviation of about 10 days. This means you're more likely to go into labor on one of the days close to your due date. For instance, about half of all babies are born within a week of their date. Scroll to the bottom of this page if you want to know more about where I got these numbers.

The following dates are based on an estimated due date of December 10th, 2018.

Change due date:
Month Day Year
Date Progress Overall probability of
spontaneous labor
Current probability of
spontaneous labor
probability of a pregnant woman at this stage going into labor
On this date By this date On this date By this date On this date Within 3 days Within 5 days Within 7 days
Monday November 5th, 2018 35W, 0D 0.01% 0.02% -% -% -% 0.1% 0.1% 0.2%
Tuesday November 6th, 2018 35W, 1D 0.01% 0.03% -% -% -% 0.1% 0.2% 0.3%
Wednesday November 7th, 2018 35W, 2D 0.02% 0.05% -% -% -% 0.1% 0.2% 0.4%
Thursday November 8th, 2018 35W, 3D 0.02% 0.07% -% -% -% 0.1% 0.3% 0.6%
Friday November 9th, 2018 35W, 4D 0.03% 0.1% -% -% -% 0.2% 0.4% 0.7%
Saturday November 10th, 2018 35W, 5D 0.04% 0.13% -% -% -% 0.2% 0.5% 0.9%
Sunday November 11th, 2018 35W, 6D 0.06% 0.19% -% -% 0.1% 0.3% 0.6% 1.2%
Monday November 12th, 2018 36W, 0D 0.08% 0.26% -% -% 0.1% 0.4% 0.8% 1.5%
Tuesday November 13th, 2018 36W, 1D 0.1% 0.35% -% -% 0.1% 0.5% 1% 1.9%
Wednesday November 14th, 2018 36W, 2D 0.14% 0.47% -% -% 0.1% 0.6% 1.3% 2.4%
Thursday November 15th, 2018 36W, 3D 0.18% 0.62% -% -% 0.2% 0.8% 1.7% 3%
Friday November 16th, 2018 36W, 4D 0.22% 0.82% -% -% 0.2% 1% 2.1% 3.7%
Saturday November 17th, 2018 36W, 5D 0.28% 1.07% -% -% 0.3% 1.2% 2.5% 4.5%
Sunday November 18th, 2018 36W, 6D 0.35% 1.39% -% -% 0.4% 1.5% 3.1% 5.4%
Monday November 19th, 2018 37W, 0D 0.44% 1.79% -% -% 0.4% 1.8% 3.8% 6.4%
Tuesday November 20th, 2018 37W, 1D 0.54% 2.28% -% -% 0.6% 2.2% 4.5% 7.6%
Wednesday November 21st, 2018 37W, 2D 0.66% 2.87% -% -% 0.7% 2.7% 5.4% 8.9%
Thursday November 22nd, 2018 37W, 3D 0.79% 3.59% -% -% 0.8% 3.2% 6.3% 10.4%
Friday November 23rd, 2018 37W, 4D 0.94% 4.46% -% -% 1% 3.8% 7.4% 11.9%
Saturday November 24th, 2018 37W, 5D 1.11% 5.48% -% -% 1.2% 4.4% 8.6% 13.7%
Sunday November 25th, 2018 37W, 6D 1.3% 6.68% -% -% 1.4% 5.2% 9.8% 15.5%
Monday November 26th, 2018 38W, 0D 1.5% 8.08% -% -% 1.6% 6% 11.2% 17.5%
Tuesday November 27th, 2018 38W, 1D 1.71% 9.68% -% -% 1.9% 6.9% 12.7% 19.7%
Wednesday November 28th, 2018 38W, 2D 1.94% 11.51% -% -% 2.2% 7.8% 14.3% 21.9%
Thursday November 29th, 2018 38W, 3D 2.18% 13.57% -% -% 2.5% 8.8% 16% 24.2%
Friday November 30th, 2018 38W, 4D 2.42% 15.87% -% -% 2.9% 9.9% 17.8% 26.6%
Saturday December 1st, 2018 38W, 5D 2.66% 18.41% -% -% 3.3% 11.1% 19.7% 29%
Sunday December 2nd, 2018 38W, 6D 2.9% 21.19% -% -% 3.7% 12.3% 21.6% 31.5%
Monday December 3rd, 2018 39W, 0D 3.12% 24.2% -% -% 4.1% 13.5% 23.6% 34%
Tuesday December 4th, 2018 39W, 1D 3.33% 27.43% -% -% 4.6% 14.9% 25.6% 36.6%
Wednesday December 5th, 2018 39W, 2D 3.52% 30.85% -% -% 5.1% 16.2% 27.7% 39.2%
Thursday December 6th, 2018 39W, 3D 3.68% 34.46% -% -% 5.6% 17.6% 29.8% 41.7%
Friday December 7th, 2018 39W, 4D 3.81% 38.21% -% -% 6.2% 19.1% 31.9% 44.2%
Saturday December 8th, 2018 39W, 5D 3.91% 42.07% -% -% 6.7% 20.6% 34% 46.7%
Sunday December 9th, 2018 39W, 6D 3.97% 46.02% -% -% 7.4% 22.1% 36.2% 49.2%
Monday December 10th, 2018 40W, 0D 3.99% 50% 8% 0% 8% 23.6% 38.3% 51.6%
Tuesday December 11th, 2018 40W, 1D 3.97% 53.98% 7.9% 8% 8.6% 25.1% 40.4% 54%
Wednesday December 12th, 2018 40W, 2D 3.91% 57.93% 7.8% 15.9% 9.3% 26.7% 42.5% 56.2%
Thursday December 13th, 2018 40W, 3D 3.81% 61.79% 7.6% 23.6% 10% 28.2% 44.5% 58.5%
Friday December 14th, 2018 40W, 4D 3.68% 65.54% 7.4% 31.1% 10.7% 29.8% 46.6% 60.6%
Saturday December 15th, 2018 40W, 5D 3.52% 69.15% 7% 38.3% 11.4% 31.3% 48.6% 62.7%
Sunday December 16th, 2018 40W, 6D 3.33% 72.57% 6.7% 45.1% 12.1% 32.9% 50.5% 64.7%
Monday December 17th, 2018 41W, 0D 3.12% 75.8% 6.2% 51.6% 12.9% 34.4% 52.4% 66.6%
Tuesday December 18th, 2018 41W, 1D 2.9% 78.81% 5.8% 57.6% 13.7% 36% 54.3% 68.5%
Wednesday December 19th, 2018 41W, 2D 2.66% 81.59% 5.3% 63.2% 14.4% 37.5% 56.1% 70.2%
Thursday December 20th, 2018 41W, 3D 2.42% 84.13% 4.8% 68.3% 15.2% 39% 57.9% 71.9%
Friday December 21st, 2018 41W, 4D 2.18% 86.43% 4.4% 72.9% 16.1% 40.5% 59.6% 73.5%
Saturday December 22nd, 2018 41W, 5D 1.94% 88.49% 3.9% 77% 16.9% 42% 61.3% 75.1%
Sunday December 23rd, 2018 41W, 6D 1.71% 90.32% 3.4% 80.6% 17.7% 43.4% 62.9% 76.4%
Monday December 24th, 2018 42W, 0D 1.5% 91.92% 3% 83.8% 18.6% 44.8% 64.5% 77.8%
Tuesday December 25th, 2018 42W, 1D 1.3% 93.32% 2.6% 86.6% 19.5% 46.3% 65.9% 79.2%
Wednesday December 26th, 2018 42W, 2D 1.11% 94.52% 2.2% 89% 20.3% 47.6% 67.3% 80.5%
Thursday December 27th, 2018 42W, 3D 0.94% 95.54% 1.9% 91.1% 21.1% 48.9% 68.8% 81.6%
Friday December 28th, 2018 42W, 4D 0.79% 96.41% 1.6% 92.8% 22% 50.1% 70.2% 82.7%
Saturday December 29th, 2018 42W, 5D 0.66% 97.13% 1.3% 94.3% 23% 51.6% 71.4% 83.6%
Sunday December 30th, 2018 42W, 6D 0.54% 97.72% 1.1% 95.4% 23.7% 53.1% 72.8% 84.6%
Monday December 31st, 2018 43W, 0D 0.44% 98.21% 0.9% 96.4% 24.6% 54.2% 73.7% 85.5%
Tuesday January 1st, 2019 43W, 1D 0.35% 98.61% 0.7% 97.2% 25.2% 55.4% 74.8% 86.3%
Wednesday January 2nd, 2019 43W, 2D 0.28% 98.93% 0.6% 97.9% 26.2% 56.1% 75.7% 87.9%
Thursday January 3rd, 2019 43W, 3D 0.22% 99.18% 0.4% 98.4% 26.8% 57.3% 76.8% -%
Friday January 4th, 2019 43W, 4D 0.18% 99.38% 0.4% 98.8% 29% 58.1% 79% -%
Saturday January 5th, 2019 43W, 5D 0.14% 99.53% 0.3% 99.1% 29.8% 59.6% -% -%
Sunday January 6th, 2019 43W, 6D 0.1% 99.65% 0.2% 99.3% 28.6% 62.9% -% -%
Monday January 7th, 2019 44W, 0D 0.08% 99.74% 0.2% 99.5% 30.8% -% -% -%
Tuesday January 8th, 2019 44W, 1D 0.06% 99.81% 0.1% 99.6% 31.6% -% -% -%
Wednesday January 9th, 2019 44W, 2D 0.04% 99.87% 0.1% 99.7% 30.8% -% -% -%

Probability of labor on a given day

Probability of labor by a given day

Notes and disclaimers

All percentages are estimates based on mathematical averages and should not be taken terribly seriously... just because you only have 5% chance of going into labor two weeks early, that doesn't mean you should schedule a trip to the bahamas that weekend (see xkcd to get what I mean here).

You should (obviously) listen to your doctor or midwife on all matters related to pregnancy and childbirth. Just because this chart tells you that a 42W pregnant woman has a high chance of delivering in the next seven days, it doesn't mean it's healthy for her to be pregnant for seven more days. If your doctor wants to increase probability of delivery by inducing labor, there's probably a good reason.

Finding good distribution statistics on spontaneous labor is interesting. I have not found a study with an exact daily breakdown of when babies are born. However I have read way too much on this topic, so I can tell you that my favorite published research is The length of human pregnancy as calculated by ultrasonographic measurement of the fetal biparietal diameter (H. Kieler, O. Axelsson, S. Nilsson, U. Waldenströ) which a very nice table of 10 published studies, which found various means between 272-283 days. The study contributes their own results as well, analyzing nearly 2000 mothers who went into labor spontaneously, and there's graphs of what they found. They found a mean around 280 days, and standard deviations between 8-11 days. There's a big list of other studies and answers in the Introduction to my due date survey results.

Which leads to this topic... I am also in the process of collecting my own statistics. If you have had a baby, please take my due date survey. Oddly enough, the numbers I've collected so far support my messy hunch that pregnancy length has a 40-week mean and 9-10 day standard deviation. So go me.

Anyway if you have better research, drop me an e-mail (spacefem@spacefem.com).

Charts are generated by flot.

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Recent Comments

For more support, encouragement, Q&A, you are invited to join our pregnancy forum. We are dedicated to answering complicated questions as logically as we possibly can.

kids' mail subscriptions

Wed Dec 5 5:44 PM by melsbells in Pregnancy & Parenting

The books on Little Feminist look really great, lots of books featuring actual people instead of anthropomorphic animals.



I remember having a Highlights magazine once or twice as a kid, but I don't remember being interested in it or a connection to books.


housemates + newborn = ?

Thu Aug 2 11:57 AM by melsbells in Pregnancy & Parenting

I live with my in-laws, and while there will certainly be a lot of differences from your situation, maybe there's enough similarities that my experience could be useful to you. I think the biggest thing is that everyone has their own space. Our house is sort of divided in two, so we can take the kid to our end during a tantrum. I think that distance helps, not just with in-laws not wanting to hear screaming, but as a sort of physical signal for the kid to calm down. We lived in an apartment when the kid was first born and our neighbors there probably heard more screaming/crying due to proximity.



My father-in-law spends a lot of time with the kid, mostly by choice. I sometimes wish we had more of a schedule, because at the moment, naps and bedtime are the only semi-guaranteed breaks for anyone. My spouse and father-in-law both work from home free-lance, so they don't actually have a schedule for when they need to be left alone, but at least my father-in-law has more warning with jobs scheduled out in advance.


My Ectopic Pregnancy

Tue Jan 23 8:47 PM by rowan in Pregnancy & Parenting

FYI we have a general culture in the pregnancy forum here about sharing similar stories as a way to offer support, and also about giving any medical knowledge that we've come across, since pregnancy is generally not talked about as much as it should be and you find information in random places. Since you haven't been around until now you probably didn't know that, and mels' post is well in line with forum guidelines and norms. Please don't go all mod martyr on us now that you're only just back. This is me as a friend speaking here, not with my modhat on.



I'm sorry for your loss. Ectopic pregnancies are scary, and I would like to go punch that first doctor in the face for you.



PPD is awful too. :( I hope you can get through it.


gender recognition

Thu Nov 2 1:03 PM by Nech in Pregnancy & Parenting


You can continue discussing with him the difference of a boy and a girl. Have him socialize too with the same gender. There's nothing wrong if you have go with opposite sex as long as he understands what/who he is.


So do you feel hanging out with the opposite gender at a young age can confuse a person's gender identity?


leftist parenting and gender [split from gender recognition]

Sat Sep 23 11:52 AM by Unvoiced_Apollo in Pregnancy & Parenting


gender recognition.">



If a boy who has a penis asks if he's a boy and you don't just say yes, then that's straight up lunacy.



What he decides to do with that boyhood or how he dresses is up to him. But if you're born with a penis you're a boy.



Making it airy fairy when, statistically, scientifically, less than 1% of 1% of children born have true gender dysphoria, is immoral and wrong. It's also a sign of our troubled times.


This is just my anecdotal experience but...



I have experienced bullying based on simply engaging in normal children's play with girls. Insults were attacks on both me and the girls. But I NEVER questioned my gender as a male. So if a child asks me if he's a boy and was identified biologically as one, I am going to question what influences are on the child before I answer.


How important is school?

Thu Nov 22 9:05 PM by Skeezy in Pregnancy & Parenting

I think the most important factor in any school is how much the teachers care about the students. Another important element is safety and how interactions between students can substract from learning. Many parents go to jail for quite lengthy sentences for trying to send to their kids to a safe good school.



I would say its very important, because what you learn shapes and molds yours views that make you who you are.


Unplanned, polyamorous pregnancy situation

Sun Apr 29 12:18 PM by metawidget in Pregnancy & Parenting

I'm glad you have been communicating and working things out. I wish you lots of health and love as you wrote the next chapter of this story.


I might be pregnant...

Fri Jan 5 3:16 AM by Aum in Pregnancy & Parenting


Aum, my partner and I were just discussing this. He was surprised by my taking the hard line that stopping BC or poking holes in condoms or something like that is rape, making the woman a rapist. Which should result in jail time, so she should lose custody, which should go to the father and now he has the choice of keeping the baby or putting them up for adoption.

It's unfortunate that you can't prove such a thing, but hopefully if it was actually taken seriously women would be less likely to do it because it would at least be explicitly called rape.


I understand how the justice system and the family courts would look at it. They see it as the man's sperm made it to the egg so somehow he wasn't protecting himself, he made the choice, yada yada. There's no way to prove that the woman was manipulative, withdrew BC, or "poked holes in the condom" (I think that's unheard of, but anyway).


When do you outsource parenting?

Sat Oct 14 7:47 PM by rowan in Pregnancy & Parenting

yeah I do a ton of supplemental history... :(


It might be time for a baby.

Sat Sep 16 1:59 PM by Sonic# in Pregnancy & Parenting

I got curious on the question of single parent families. Definitely, I think financial stability or having some sort of support network (family, friends) is better than not having it.



I found this article ( https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4886836/ ). The article does point out that several factors adjust child adjustment, like finances and parental stress. Merely being a single parent? Not a factor:
The findings suggest that solo motherhood, in itself, does not result in psychological problems for children.

The lit review at the beginning of the article adds some specificity here. What seems hard on kids is not single parenthood itself; it's often the divorce that results in a single parent being involved. These studies have consistently shown that children whose parents divorce are more likely to show emotional and behavioral problems than are children in intact families (Amato, 2000, 2001, 2005; Coleman & Glenn, 2009; Hetherington & Stanley-Hagan, 1999; Pryor & Rodgers, 2001). However, the children’s difficulties appear to be largely associated with aspects of the divorce, rather than single-parenthood, in itself. Then there are people who become single parents, but not by choice. That's also rough, often because these parents lack the financial stability and stability to do well. So the article is really looking at single parents by choice. They can raise children as well as two-parent households.


How the 2nd pregnancy / labor was different from the first

Thu Sep 27 8:20 PM by antfancier in Pregnancy & Parenting

I haven’t been around for a long time, but I’m back and pregnant again. Only 6 weeks, so I can’t really comment much, but this time around it has been easier so far. Not easy, but considering I’m working and have a 2.5yr old (neither of which applied to last pregnancy), I thought I’d feel much worse. I still have ALL the symptoms and they all started at 3 weeks, just like last time (and the same as a chemical pregnancy I had too) but they don’t seem to be as constant as before. I’m really glad about that! The only thing that’s worse is back ache, ligament pain, general body aches. I assume it’s because my body is already exhausted and broken from my toddler.


posting pictures of kids and privacy

Wed Apr 25 7:29 AM by juliabonl17 in Pregnancy & Parenting

Usually, we don't share photos of our children in social media. Sometimes I can send some photos to close friends. I keep my personal life in quiet. Share with family only.


I had my 2nd baby!!!!

Wed Jan 3 8:21 PM by MFS in Pregnancy & Parenting

OMG BABY!



I am still dealing with the fact that your 11 year old is an actual 11 year old.


on being semi-pregnant

Tue Oct 3 7:18 PM by geldofc in Pregnancy & Parenting

congratulations!! i've never been pregnant but i'm jealous. i'm having baby fever lately.


Clock-Ticking

Wed Sep 13 6:58 PM by geldofc in Pregnancy & Parenting

my clock started ticking in my 20s and i would love a child at 30 now but i want to live how i want for a few more years, and have my career established. i don't see parenthood for another 5 years.



egg freezing seems like a good option esp if you have extra time and money.