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 17th, 2017.

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
Sunday November 12th, 2017 35W, 0D 0.01% 0.02% -% -% -% 0.1% 0.1% 0.2%
Monday November 13th, 2017 35W, 1D 0.01% 0.03% -% -% -% 0.1% 0.2% 0.3%
Tuesday November 14th, 2017 35W, 2D 0.02% 0.05% -% -% -% 0.1% 0.2% 0.4%
Wednesday November 15th, 2017 35W, 3D 0.02% 0.07% -% -% -% 0.1% 0.3% 0.6%
Thursday November 16th, 2017 35W, 4D 0.03% 0.1% -% -% -% 0.2% 0.4% 0.7%
Friday November 17th, 2017 35W, 5D 0.04% 0.13% -% -% -% 0.2% 0.5% 0.9%
Saturday November 18th, 2017 35W, 6D 0.06% 0.19% -% -% 0.1% 0.3% 0.6% 1.2%
Sunday November 19th, 2017 36W, 0D 0.08% 0.26% -% -% 0.1% 0.4% 0.8% 1.5%
Monday November 20th, 2017 36W, 1D 0.1% 0.35% -% -% 0.1% 0.5% 1% 1.9%
Tuesday November 21st, 2017 36W, 2D 0.14% 0.47% -% -% 0.1% 0.6% 1.3% 2.4%
Wednesday November 22nd, 2017 36W, 3D 0.18% 0.62% -% -% 0.2% 0.8% 1.7% 3%
Thursday November 23rd, 2017 36W, 4D 0.22% 0.82% -% -% 0.2% 1% 2.1% 3.7%
Friday November 24th, 2017 36W, 5D 0.28% 1.07% -% -% 0.3% 1.2% 2.5% 4.5%
Saturday November 25th, 2017 36W, 6D 0.35% 1.39% -% -% 0.4% 1.5% 3.1% 5.4%
Sunday November 26th, 2017 37W, 0D 0.44% 1.79% -% -% 0.4% 1.8% 3.8% 6.4%
Monday November 27th, 2017 37W, 1D 0.54% 2.28% -% -% 0.6% 2.2% 4.5% 7.6%
Tuesday November 28th, 2017 37W, 2D 0.66% 2.87% -% -% 0.7% 2.7% 5.4% 8.9%
Wednesday November 29th, 2017 37W, 3D 0.79% 3.59% -% -% 0.8% 3.2% 6.3% 10.4%
Thursday November 30th, 2017 37W, 4D 0.94% 4.46% -% -% 1% 3.8% 7.4% 11.9%
Friday December 1st, 2017 37W, 5D 1.11% 5.48% -% -% 1.2% 4.4% 8.6% 13.7%
Saturday December 2nd, 2017 37W, 6D 1.3% 6.68% -% -% 1.4% 5.2% 9.8% 15.5%
Sunday December 3rd, 2017 38W, 0D 1.5% 8.08% -% -% 1.6% 6% 11.2% 17.5%
Monday December 4th, 2017 38W, 1D 1.71% 9.68% -% -% 1.9% 6.9% 12.7% 19.7%
Tuesday December 5th, 2017 38W, 2D 1.94% 11.51% -% -% 2.2% 7.8% 14.3% 21.9%
Wednesday December 6th, 2017 38W, 3D 2.18% 13.57% -% -% 2.5% 8.8% 16% 24.2%
Thursday December 7th, 2017 38W, 4D 2.42% 15.87% -% -% 2.9% 9.9% 17.8% 26.6%
Friday December 8th, 2017 38W, 5D 2.66% 18.41% -% -% 3.3% 11.1% 19.7% 29%
Saturday December 9th, 2017 38W, 6D 2.9% 21.19% -% -% 3.7% 12.3% 21.6% 31.5%
Sunday December 10th, 2017 39W, 0D 3.12% 24.2% -% -% 4.1% 13.5% 23.6% 34%
Monday December 11th, 2017 39W, 1D 3.33% 27.43% -% -% 4.6% 14.9% 25.6% 36.6%
Tuesday December 12th, 2017 39W, 2D 3.52% 30.85% -% -% 5.1% 16.2% 27.7% 39.2%
Wednesday December 13th, 2017 39W, 3D 3.68% 34.46% -% -% 5.6% 17.6% 29.8% 41.7%
Thursday December 14th, 2017 39W, 4D 3.81% 38.21% -% -% 6.2% 19.1% 31.9% 44.2%
Friday December 15th, 2017 39W, 5D 3.91% 42.07% -% -% 6.7% 20.6% 34% 46.7%
Saturday December 16th, 2017 39W, 6D 3.97% 46.02% -% -% 7.4% 22.1% 36.2% 49.2%
Sunday December 17th, 2017 40W, 0D 3.99% 50% 8% 0% 8% 23.6% 38.3% 51.6%
Monday December 18th, 2017 40W, 1D 3.97% 53.98% 7.9% 8% 8.6% 25.1% 40.4% 54%
Tuesday December 19th, 2017 40W, 2D 3.91% 57.93% 7.8% 15.9% 9.3% 26.7% 42.5% 56.2%
Wednesday December 20th, 2017 40W, 3D 3.81% 61.79% 7.6% 23.6% 10% 28.2% 44.5% 58.5%
Thursday December 21st, 2017 40W, 4D 3.68% 65.54% 7.4% 31.1% 10.7% 29.8% 46.6% 60.6%
Friday December 22nd, 2017 40W, 5D 3.52% 69.15% 7% 38.3% 11.4% 31.3% 48.6% 62.7%
Saturday December 23rd, 2017 40W, 6D 3.33% 72.57% 6.7% 45.1% 12.1% 32.9% 50.5% 64.7%
Sunday December 24th, 2017 41W, 0D 3.12% 75.8% 6.2% 51.6% 12.9% 34.4% 52.4% 66.6%
Monday December 25th, 2017 41W, 1D 2.9% 78.81% 5.8% 57.6% 13.7% 36% 54.3% 68.5%
Tuesday December 26th, 2017 41W, 2D 2.66% 81.59% 5.3% 63.2% 14.4% 37.5% 56.1% 70.2%
Wednesday December 27th, 2017 41W, 3D 2.42% 84.13% 4.8% 68.3% 15.2% 39% 57.9% 71.9%
Thursday December 28th, 2017 41W, 4D 2.18% 86.43% 4.4% 72.9% 16.1% 40.5% 59.6% 73.5%
Friday December 29th, 2017 41W, 5D 1.94% 88.49% 3.9% 77% 16.9% 42% 61.3% 75.1%
Saturday December 30th, 2017 41W, 6D 1.71% 90.32% 3.4% 80.6% 17.7% 43.4% 62.9% 76.4%
Sunday December 31st, 2017 42W, 0D 1.5% 91.92% 3% 83.8% 18.6% 44.8% 64.5% 77.8%
Monday January 1st, 2018 42W, 1D 1.3% 93.32% 2.6% 86.6% 19.5% 46.3% 65.9% 79.2%
Tuesday January 2nd, 2018 42W, 2D 1.11% 94.52% 2.2% 89% 20.3% 47.6% 67.3% 80.5%
Wednesday January 3rd, 2018 42W, 3D 0.94% 95.54% 1.9% 91.1% 21.1% 48.9% 68.8% 81.6%
Thursday January 4th, 2018 42W, 4D 0.79% 96.41% 1.6% 92.8% 22% 50.1% 70.2% 82.7%
Friday January 5th, 2018 42W, 5D 0.66% 97.13% 1.3% 94.3% 23% 51.6% 71.4% 83.6%
Saturday January 6th, 2018 42W, 6D 0.54% 97.72% 1.1% 95.4% 23.7% 53.1% 72.8% 84.6%
Sunday January 7th, 2018 43W, 0D 0.44% 98.21% 0.9% 96.4% 24.6% 54.2% 73.7% 85.5%
Monday January 8th, 2018 43W, 1D 0.35% 98.61% 0.7% 97.2% 25.2% 55.4% 74.8% 86.3%
Tuesday January 9th, 2018 43W, 2D 0.28% 98.93% 0.6% 97.9% 26.2% 56.1% 75.7% 87.9%
Wednesday January 10th, 2018 43W, 3D 0.22% 99.18% 0.4% 98.4% 26.8% 57.3% 76.8% -%
Thursday January 11th, 2018 43W, 4D 0.18% 99.38% 0.4% 98.8% 29% 58.1% 79% -%
Friday January 12th, 2018 43W, 5D 0.14% 99.53% 0.3% 99.1% 29.8% 59.6% -% -%
Saturday January 13th, 2018 43W, 6D 0.1% 99.65% 0.2% 99.3% 28.6% 62.9% -% -%
Sunday January 14th, 2018 44W, 0D 0.08% 99.74% 0.2% 99.5% 30.8% -% -% -%
Monday January 15th, 2018 44W, 1D 0.06% 99.81% 0.1% 99.6% 31.6% -% -% -%
Tuesday January 16th, 2018 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.

I might be pregnant...

Sat Dec 16 8:35 PM by Aum in Pregnancy & Parenting


I never thought about how stopping b/c could be a form of stealthing. edit: it's actually called reproductive coercion and stealthing is the removal of a condom which could also expose someone to a wider range of STDs. I hope long-term couples talk about things like consent and b/c and intoxication prior to anything happening. You should tell your partner asap about stopping your birth control, OP.


I don't care to mince words. In principle, it's the exact same thing: one person engaging in a sexual act with another on the premise that there is a certain level of agreed upon safety, but one person is secretly not maintaining that safety. It's a consent issue and therefore a rape issue.



Of course, the courts won't care if she decides to file for child support. He won't be able to prove that she did anything wrong and even if he could they would still blame him for not protecting himself with a condom. The violation of a sacred trust between two people in an LTR is not even taken into account.


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 to deal with opinionated toddlers (or babies or kids)

Tue Aug 1 1:57 AM by rowan in Pregnancy & Parenting

Ooof. My kid is very social, needs to be around someone all the time. It's ... challenging, as you've found. It does get better as they gain their own interests. But it took a long time to get past clingy.



Not having read your post, but just the heading, my response was "wine." But after reading your post, I thought "wine."

Yes. After bedtime.



Also, honestly the only way we made it through was we would take turns being the center of focus. We still do this, divide and conquer (and she's only one kid, hell). Also, I know people are like really limit screen time BUT if you really need to get something done one episode of e.g. Daniel Tiger or Paw Patrol or whatever isn't gonna be too bad. I think DarkOne has some good ideas too.



Good luck.


Happiest Baby on the Block

Wed Jul 12 4:52 PM by antfancier in Pregnancy & Parenting

My mum gave me 'Your Baby and Child' by Penelope Leach, which is what she used when she had me. It covers from birth to five years. I read the first section about newborns in preparation. After having the baby, I realised I have zero time or brain power to do anything so I never got around to the rest of it. In general, I liked the book though. It's a simple overview and has nice color photos.


I had my 2nd baby!!!!

Sat Dec 16 6:31 AM by geldofc in Pregnancy & Parenting

Congratulations! I love the little mitts. I'm probably going to buy a ton of those just because they're so cute.


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.


bad reasons for having a baby

Tue Aug 1 1:47 AM by rowan in Pregnancy & Parenting

but I take them to restaurants so I know they end up hating 90% of the things they ask for.
:lol:



- kid would like a sibling

- maybe people are right about end of life stuff



That's about it. I hated being pregnant, the last time I was pregnant the hormones were... really awful. Plus kid is now pretty big so another one would be weird and we gave away all our stuff. ;)


how do you travel?

Mon Jun 19 11:00 AM by DarkOne in Pregnancy & Parenting

We're traveling with a 2 yo and a 4yo this week. A 2 hr flight connecting to a 4 hr flight. I broke down and got tablets and headphones, now I just need to load them with movies/games. I'm packing treats and stickers and crayons and notepads. I'm almost positive I'll be carrying on a (very compactable) pillow, 'cause they don't give those out anymore on board. I'm banning toys that can roll several aisles fwd or back when inevitably dropped (besides the crayons). I was planning on gum for ascent/descent, but I think the suckers for the 2yo will be better. I'm so not looking forward to these flights. Maybe the kids will surprise me and be awesome. I'm not worried about the 4yo. But the 2yo...


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.


Postpartum issues: things that can go wrong after

Wed Aug 9 5:24 PM by rowan in Pregnancy & Parenting

ugh that totes doesn't just happen during c-section. I had a friend who found out when she was having (other) surgery years later and they stitched her up since "they were in there anyway". Honestly I think I also have it but it doesn't cause problems *most* of the time (sometimes stabby pain but no one takes it seriously so idk).


Just Can't Let It Go

Wed Jul 26 1:18 AM by Taurwen in Pregnancy & Parenting

We didn't find out specifically because we didn't want a lot of pink stuff if it was a girl.



Somehow MIL has still given us a ton of pink clothing that she'll change him into everytime she comes over.

I hate pink.


Another baby stars

Thu Jun 15 6:54 AM by StarsInUrEye in Pregnancy & Parenting

Thanks for the congratulations and encouragement.



I had an appointment with the obgyn today. He seems to think I'm even farther along than he originally thought. I didn't have an ultrasound. He just went by the size of my uterus. It's well over my belly button now. He's sending me to a high risk Dr. Asap and then I'm suppost to see him again on the 29th. By then he said they will have a better idea as to how far along I actually am. So far the pregnancy is going well. I did have complications with my first one and went to a specialist but this time I'm being referred to one because I'm old lol. They automatically send women when they are 35 and older.