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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 January 15th, 2014.

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
Wednesday December 11th, 2013 35W, 0D 0.01% 0.02% -% -% -% 0.1% 0.1% 0.2%
Thursday December 12th, 2013 35W, 1D 0.01% 0.03% -% -% -% 0.1% 0.2% 0.3%
Friday December 13th, 2013 35W, 2D 0.02% 0.05% -% -% -% 0.1% 0.2% 0.4%
Saturday December 14th, 2013 35W, 3D 0.02% 0.07% -% -% -% 0.1% 0.3% 0.6%
Sunday December 15th, 2013 35W, 4D 0.03% 0.1% -% -% -% 0.2% 0.4% 0.7%
Monday December 16th, 2013 35W, 5D 0.04% 0.13% -% -% -% 0.2% 0.5% 0.9%
Tuesday December 17th, 2013 35W, 6D 0.06% 0.19% -% -% 0.1% 0.3% 0.6% 1.2%
Wednesday December 18th, 2013 36W, 0D 0.08% 0.26% -% -% 0.1% 0.4% 0.8% 1.5%
Thursday December 19th, 2013 36W, 1D 0.1% 0.35% -% -% 0.1% 0.5% 1% 1.9%
Friday December 20th, 2013 36W, 2D 0.14% 0.47% -% -% 0.1% 0.6% 1.3% 2.4%
Saturday December 21st, 2013 36W, 3D 0.18% 0.62% -% -% 0.2% 0.8% 1.7% 3%
Sunday December 22nd, 2013 36W, 4D 0.22% 0.82% -% -% 0.2% 1% 2.1% 3.7%
Monday December 23rd, 2013 36W, 5D 0.28% 1.07% -% -% 0.3% 1.2% 2.5% 4.5%
Tuesday December 24th, 2013 36W, 6D 0.35% 1.39% -% -% 0.4% 1.5% 3.1% 5.4%
Wednesday December 25th, 2013 37W, 0D 0.44% 1.79% -% -% 0.4% 1.8% 3.8% 6.4%
Thursday December 26th, 2013 37W, 1D 0.54% 2.28% -% -% 0.6% 2.2% 4.5% 7.6%
Friday December 27th, 2013 37W, 2D 0.66% 2.87% -% -% 0.7% 2.7% 5.4% 8.9%
Saturday December 28th, 2013 37W, 3D 0.79% 3.59% -% -% 0.8% 3.2% 6.3% 10.4%
Sunday December 29th, 2013 37W, 4D 0.94% 4.46% -% -% 1% 3.8% 7.4% 11.9%
Monday December 30th, 2013 37W, 5D 1.11% 5.48% -% -% 1.2% 4.4% 8.6% 13.7%
Tuesday December 31st, 2013 37W, 6D 1.3% 6.68% -% -% 1.4% 5.2% 9.8% 15.5%
Wednesday January 1st, 2014 38W, 0D 1.5% 8.08% -% -% 1.6% 6% 11.2% 17.5%
Thursday January 2nd, 2014 38W, 1D 1.71% 9.68% -% -% 1.9% 6.9% 12.7% 19.7%
Friday January 3rd, 2014 38W, 2D 1.94% 11.51% -% -% 2.2% 7.8% 14.3% 21.9%
Saturday January 4th, 2014 38W, 3D 2.18% 13.57% -% -% 2.5% 8.8% 16% 24.2%
Sunday January 5th, 2014 38W, 4D 2.42% 15.87% -% -% 2.9% 9.9% 17.8% 26.6%
Monday January 6th, 2014 38W, 5D 2.66% 18.41% -% -% 3.3% 11.1% 19.7% 29%
Tuesday January 7th, 2014 38W, 6D 2.9% 21.19% -% -% 3.7% 12.3% 21.6% 31.5%
Wednesday January 8th, 2014 39W, 0D 3.12% 24.2% -% -% 4.1% 13.5% 23.6% 34%
Thursday January 9th, 2014 39W, 1D 3.33% 27.43% -% -% 4.6% 14.9% 25.6% 36.6%
Friday January 10th, 2014 39W, 2D 3.52% 30.85% -% -% 5.1% 16.2% 27.7% 39.2%
Saturday January 11th, 2014 39W, 3D 3.68% 34.46% -% -% 5.6% 17.6% 29.8% 41.7%
Sunday January 12th, 2014 39W, 4D 3.81% 38.21% -% -% 6.2% 19.1% 31.9% 44.2%
Monday January 13th, 2014 39W, 5D 3.91% 42.07% -% -% 6.7% 20.6% 34% 46.7%
Tuesday January 14th, 2014 39W, 6D 3.97% 46.02% -% -% 7.4% 22.1% 36.2% 49.2%
Wednesday January 15th, 2014 40W, 0D 3.99% 50% -% -% 8% 23.6% 38.3% 51.6%
Thursday January 16th, 2014 40W, 1D 3.97% 53.98% -% -% 8.6% 25.1% 40.4% 54%
Friday January 17th, 2014 40W, 2D 3.91% 57.93% -% -% 9.3% 26.7% 42.5% 56.2%
Saturday January 18th, 2014 40W, 3D 3.81% 61.79% -% -% 10% 28.2% 44.5% 58.5%
Sunday January 19th, 2014 40W, 4D 3.68% 65.54% -% -% 10.7% 29.8% 46.6% 60.6%
Monday January 20th, 2014 40W, 5D 3.52% 69.15% -% -% 11.4% 31.3% 48.6% 62.7%
Tuesday January 21st, 2014 40W, 6D 3.33% 72.57% -% -% 12.1% 32.9% 50.5% 64.7%
Wednesday January 22nd, 2014 41W, 0D 3.12% 75.8% -% -% 12.9% 34.4% 52.4% 66.6%
Thursday January 23rd, 2014 41W, 1D 2.9% 78.81% -% -% 13.7% 36% 54.3% 68.5%
Friday January 24th, 2014 41W, 2D 2.66% 81.59% -% -% 14.4% 37.5% 56.1% 70.2%
Saturday January 25th, 2014 41W, 3D 2.42% 84.13% -% -% 15.2% 39% 57.9% 71.9%
Sunday January 26th, 2014 41W, 4D 2.18% 86.43% -% -% 16.1% 40.5% 59.6% 73.5%
Monday January 27th, 2014 41W, 5D 1.94% 88.49% -% -% 16.9% 42% 61.3% 75.1%
Tuesday January 28th, 2014 41W, 6D 1.71% 90.32% -% -% 17.7% 43.4% 62.9% 76.4%
Wednesday January 29th, 2014 42W, 0D 1.5% 91.92% -% -% 18.6% 44.8% 64.5% 77.8%
Thursday January 30th, 2014 42W, 1D 1.3% 93.32% -% -% 19.5% 46.3% 65.9% 79.2%
Friday January 31st, 2014 42W, 2D 1.11% 94.52% -% -% 20.3% 47.6% 67.3% 80.5%
Saturday February 1st, 2014 42W, 3D 0.94% 95.54% -% -% 21.1% 48.9% 68.8% 81.6%
Sunday February 2nd, 2014 42W, 4D 0.79% 96.41% -% -% 22% 50.1% 70.2% 82.7%
Monday February 3rd, 2014 42W, 5D 0.66% 97.13% -% -% 23% 51.6% 71.4% 83.6%
Tuesday February 4th, 2014 42W, 6D 0.54% 97.72% -% -% 23.7% 53.1% 72.8% 84.6%
Wednesday February 5th, 2014 43W, 0D 0.44% 98.21% -% -% 24.6% 54.2% 73.7% 85.5%
Thursday February 6th, 2014 43W, 1D 0.35% 98.61% -% -% 25.2% 55.4% 74.8% 86.3%
Friday February 7th, 2014 43W, 2D 0.28% 98.93% -% -% 26.2% 56.1% 75.7% 87.9%
Saturday February 8th, 2014 43W, 3D 0.22% 99.18% -% -% 26.8% 57.3% 76.8% -%
Sunday February 9th, 2014 43W, 4D 0.18% 99.38% -% -% 29% 58.1% 79% -%
Monday February 10th, 2014 43W, 5D 0.14% 99.53% -% -% 29.8% 59.6% -% -%
Tuesday February 11th, 2014 43W, 6D 0.1% 99.65% -% -% 28.6% 62.9% -% -%
Wednesday February 12th, 2014 44W, 0D 0.08% 99.74% -% -% 30.8% -% -% -%
Thursday February 13th, 2014 44W, 1D 0.06% 99.81% -% -% 31.6% -% -% -%
Friday February 14th, 2014 44W, 2D 0.04% 99.87% -% -% 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.

10 things you can leave off the baby registry

Fri Jan 30 9:52 AM by Aum in Pregnancy & Parenting

Omg hilarious and so well done, thanks for writing that Spacefem! The part about diaper baskets made me lmao


Because judging other parents is absurd.

Thu Jan 29 12:55 PM by melsbells in Pregnancy & Parenting

What's crazysauce and obviously wrong to you might easily just be someone else's "personal choice" that they say you have "no right to judge".
Just thinking of our own personal opinions on what's crazysauce and what's personal choice, I think we'd find a lot of conflict. For example, I think corporal punishment is going too far. It's also grounds for having one's kids taken away where I currently live. However, I know my parents don't feel the same way. I take it that the line of appropriate physical punishment is very different for people throughout the U.S. based on reactions this past year to NFL players phsyically repremanding their kids.
I also know that some others think I'm depriving my kid with some choices that my spouse and I make, such as diet or not getting our kid baptized.
The point is, people often assume that there is a universal RIGHT WAY FOR ALL no matter what, when of course for MOST things there is some gray area. I agree we shouldn't paper over serious discussions and tell women to stop voicing their opinions, but I think everyone could benefit from a little kindness and empathy.


sleep humor

Fri Jan 23 7:13 PM by rowan in Pregnancy & Parenting

Here's a really funny humor bit about sleep, but the same general idea can apply to pretty much any "advice" given to new parents.

"I bought all the top books on baby sleep and development. I read through them all, as well as several blogs and sleep websites. I gathered lots of advice:"

https://chimericalcapuchin.wordpress.co ... babybooks/


Work

Thu Jan 15 9:17 PM by bigdaddy in Pregnancy & Parenting

I will do cheers but in people's experiences and options I should be ok


Working as due date approaches

Mon Jan 5 6:18 AM by Bork in Pregnancy & Parenting

However long you end up staying at work, once you're in labor, PLEASE GO HOME. Or to the hospital. Because staying at work while you're in labor is hella awkward for everyone involved.


Keeping your pre-pregnancy/parenthood identity

Thu Jan 29 4:36 PM by rowan in Pregnancy & Parenting

You don't have to post at all if you don't want to! But we're here to offer support if you do want to.

I have very little time sans baby anymore
This does get a little better over time, when they're a little more autonomous. Though I still long for the day when I can just freaking go to the bathroom all by myself. (I seriously spent like 20 minutes in the bathroom the other day while the hubby was watching the kid @ a birthday party, just for that reason. I mean how sad does that sound?)

I know he requires more alone time than I do, and I know he isn't getting any more than I am.
Any chance of arranging a tag-team schedule?


name trends

Wed Jan 28 8:58 AM by Lemon in Pregnancy & Parenting

Some of my family members who work in the healthcare system have overheard some doozies.

I work in healthcare, so I can relate. I think my favourite was a kid called "Abcde" which we were assured was pronounced "Abasidee". Mirena was a cute choice, named after the contraceptive device. Then there have been some good narrative names including places of birth - e.g. "Shell" (after the baby born in a petrol station carpark) - and places of conception - e.g. "...(a suburb which I'll keep secret - just in case this somehow breaches some poor kid's privacy) bus stop."


It takes 13 million calories to raise a child!

Wed Jan 21 4:32 AM by textualorientation in Pregnancy & Parenting

Recently found out how much energy it takes to raise a child. Woah.

I'm pretty infuriated that in Canada it can cost $1,676/month for daycare, when science actually tells us we evolved to help each other raise children. I wrote a blog about this in case anyone is interested! I would really like to see this change for mothers all over Canada.

https://textualorientation.wordpress.co ... ledaycare/


Why Pocket Diapers Are Better Than Disposables

Sun Jan 11 3:31 PM by Nancy Erick in Pregnancy & Parenting

Hi everyone

A Beautiful article by writer Kathryn McDowell recently I read liked to share with you

Why Pocket Diapers Are Better Than Disposables :


As a young parent, you've no doubt heard of pocket diapers. Perhaps a neighbor or a co-worker told you about them. Or it was your babysitter, who asked you to get them soon. Well, so many families in America are today turning to pocket diapers for their little ones. But a majority still holds on to disposable diapers, while being curious about pocket diapers at the same time.

Why are diapers so great? For a start, pocket diapers come with brand new fabrics and super absorbent pads, are easy to put on, simple to take off, easy to wash and quick to dry. And they are better than disposable diapers.

They are Cheaper
Until your child is potty trained, you'd probably spend something close to $2500 to $3000 on diapers - which is quite a lot. Biodegradable disposable diapers are even costlier. But with pocket ones, you won't have to spend anything more than $350 to $400, till your child is potty trained.


Bringing home a second child - what do you wish you knew/did?

Fri Jan 2 1:27 PM by spacefem in Pregnancy & Parenting

Good topic.

Ya know, I think the one thing I remember is that it wasn't as big a deal as I thought it was. When I was pregnant I'd look at my three year old and think, "What can we do for this delicate little child whose world is about to be upside-down?" Then the baby came home, the three year old suddenly looked like a teenager to me, and I was like eh go fend for yourself kid. And honestly, she did great. She's still really sweet to her little sister.

Here are some notes:
1) New baby really does deserve some new stuff. I went through the things I'd kept from my first... nasty stained onesies, teethers, pacifiers, "pat the fur" type board books that had more than their fair share of patting (and licking, and yakking on...), I have no idea why I kept some of that. Sentimental value, engineer cheapness? Lots of clothes got reused, sure, but the plain white onesies? Splurge on the poor kiddo and spend $6 on another 4-pack.


Breastfeeding & accoutrements thereof

Thu Jan 29 1:15 PM by melsbells in Pregnancy & Parenting

I breastfed exclusively until 6 months and then started supplementing solids using baby led weaning/Ripley weaning method.

I hate breastfeeding. I don't have the courage to quit. I have over-supply/over-active let-down problems. When my baby was a newborn, hänen mouth was too small to get a good latch on my always engorged breasts. I started using a medela hand pump to pump off a little excess so my breast would be soft enough for the baby to eat. The baby never developed a great latch (since one was never needed to get all the needed milk and more) and has developed some other unhelpful habits that I haven't been able to curb (biting/pulling off without letting go first). I still cry sometimes.

The hand pump has been great. It's unobtrussive, doesn't freak me out, and because of my personal predicament, it takes less time for me to pump than most using electric pumps. The thing that has made breastfeeding slightly more tolerable is what ladyhawk mentioned.And for anyone with oversupply/leakage issues, these things, http://www.amazon.com/gp/aw/d/B000058DQ ... SY200_QL40 are the fucking tits. Pun intended. It allowed me to stop being soaked ALL THE TIME, which was especially nice to not have to deal with in the winter. The product does awkwardly give me what I think of as 1950's breasts.


34 Weeks

Fri Jan 23 11:57 PM by Sonic# in Pregnancy & Parenting

Probably not. As we pointed out in the other topic, 34 weeks isn't even on the chart because it's so rare:
http://spacefem.com/pregnant/charts/duedate1.php

You'd be better off worrying over a car accident.


Maternity Clothes

Mon Jan 19 4:17 PM by Metcodon1 in Pregnancy & Parenting

As a fat person who is currently pregnant with her second child I will say this. OF COURSE you are allowed to reproduce even if you're chubby. You're allowed to and you can even have a totally healthy pregnancy and a wonderfully healthy child (somehow, despite the fact that my husband and I are both chubby, my daughter is SKINNY - go figure).

I will say this on the topic of maternity clothes though as a fat person. Yes you may be able to wear your regular clothing longer. HOWEVER, maternity clothes make you look pregnant instead of just even fatter. For my own mental health/ego/etc. I really appreciated looking pregnant instead of just fat. Mental health is worth something too.


some quotes recently I read

Sat Jan 10 4:50 PM by Nancy Erick in Pregnancy & Parenting

i search about these quotes in google


bad language + small children

Wed Dec 31 5:38 PM by octarineoboe in Pregnancy & Parenting

I'm not a parent, but I thought it made a pretty entertaining story when my cousin's almost-three-year-old dropped an f-bomb. Her parents were a little embarrassed but also proud of her for using it correctly. It may help that her dad is a linguist and has a theory that most "swear words" are not truly profane/offensive.