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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 September 25th, 2015.

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
Friday August 21st, 2015 35W, 0D 0.01% 0.02% 0.01% 0.02% -% 0.1% 0.1% 0.2%
Saturday August 22nd, 2015 35W, 1D 0.01% 0.03% 0.01% 0.03% -% 0.1% 0.2% 0.3%
Sunday August 23rd, 2015 35W, 2D 0.02% 0.05% 0.02% 0.05% -% 0.1% 0.2% 0.4%
Monday August 24th, 2015 35W, 3D 0.02% 0.07% 0.02% 0.07% -% 0.1% 0.3% 0.6%
Tuesday August 25th, 2015 35W, 4D 0.03% 0.1% 0.03% 0.1% -% 0.2% 0.4% 0.7%
Wednesday August 26th, 2015 35W, 5D 0.04% 0.13% 0.04% 0.13% -% 0.2% 0.5% 0.9%
Thursday August 27th, 2015 35W, 6D 0.06% 0.19% 0.06% 0.19% 0.1% 0.3% 0.6% 1.2%
Friday August 28th, 2015 36W, 0D 0.08% 0.26% 0.08% 0.26% 0.1% 0.4% 0.8% 1.5%
Saturday August 29th, 2015 36W, 1D 0.1% 0.35% 0.1% 0.35% 0.1% 0.5% 1% 1.9%
Sunday August 30th, 2015 36W, 2D 0.14% 0.47% 0.14% 0.47% 0.1% 0.6% 1.3% 2.4%
Monday August 31st, 2015 36W, 3D 0.18% 0.62% 0.18% 0.62% 0.2% 0.8% 1.7% 3%
Tuesday September 1st, 2015 36W, 4D 0.22% 0.82% 0.22% 0.82% 0.2% 1% 2.1% 3.7%
Wednesday September 2nd, 2015 36W, 5D 0.28% 1.07% 0.28% 1.07% 0.3% 1.2% 2.5% 4.5%
Thursday September 3rd, 2015 36W, 6D 0.35% 1.39% 0.35% 1.39% 0.4% 1.5% 3.1% 5.4%
Friday September 4th, 2015 37W, 0D 0.44% 1.79% 0.44% 1.79% 0.4% 1.8% 3.8% 6.4%
Saturday September 5th, 2015 37W, 1D 0.54% 2.28% 0.54% 2.28% 0.6% 2.2% 4.5% 7.6%
Sunday September 6th, 2015 37W, 2D 0.66% 2.87% 0.66% 2.87% 0.7% 2.7% 5.4% 8.9%
Monday September 7th, 2015 37W, 3D 0.79% 3.59% 0.79% 3.59% 0.8% 3.2% 6.3% 10.4%
Tuesday September 8th, 2015 37W, 4D 0.94% 4.46% 0.94% 4.46% 1% 3.8% 7.4% 11.9%
Wednesday September 9th, 2015 37W, 5D 1.11% 5.48% 1.11% 5.48% 1.2% 4.4% 8.6% 13.7%
Thursday September 10th, 2015 37W, 6D 1.3% 6.68% 1.3% 6.68% 1.4% 5.2% 9.8% 15.5%
Friday September 11th, 2015 38W, 0D 1.5% 8.08% 1.5% 8.08% 1.6% 6% 11.2% 17.5%
Saturday September 12th, 2015 38W, 1D 1.71% 9.68% 1.71% 9.68% 1.9% 6.9% 12.7% 19.7%
Sunday September 13th, 2015 38W, 2D 1.94% 11.51% 1.94% 11.51% 2.2% 7.8% 14.3% 21.9%
Monday September 14th, 2015 38W, 3D 2.18% 13.57% 2.18% 13.57% 2.5% 8.8% 16% 24.2%
Tuesday September 15th, 2015 38W, 4D 2.42% 15.87% 2.42% 15.87% 2.9% 9.9% 17.8% 26.6%
Wednesday September 16th, 2015 38W, 5D 2.66% 18.41% 2.66% 18.41% 3.3% 11.1% 19.7% 29%
Thursday September 17th, 2015 38W, 6D 2.9% 21.19% 2.9% 21.19% 3.7% 12.3% 21.6% 31.5%
Friday September 18th, 2015 39W, 0D 3.12% 24.2% 3.12% 24.2% 4.1% 13.5% 23.6% 34%
Saturday September 19th, 2015 39W, 1D 3.33% 27.43% 3.33% 27.43% 4.6% 14.9% 25.6% 36.6%
Sunday September 20th, 2015 39W, 2D 3.52% 30.85% 3.52% 30.85% 5.1% 16.2% 27.7% 39.2%
Monday September 21st, 2015 39W, 3D 3.68% 34.46% 3.68% 34.46% 5.6% 17.6% 29.8% 41.7%
Tuesday September 22nd, 2015 39W, 4D 3.81% 38.21% 3.81% 38.21% 6.2% 19.1% 31.9% 44.2%
Wednesday September 23rd, 2015 39W, 5D 3.91% 42.07% 3.91% 42.07% 6.7% 20.6% 34% 46.7%
Thursday September 24th, 2015 39W, 6D 3.97% 46.02% 3.97% 46.02% 7.4% 22.1% 36.2% 49.2%
Friday September 25th, 2015 40W, 0D 3.99% 50% 3.99% 50% 8% 23.6% 38.3% 51.6%
Saturday September 26th, 2015 40W, 1D 3.97% 53.98% 3.97% 53.98% 8.6% 25.1% 40.4% 54%
Sunday September 27th, 2015 40W, 2D 3.91% 57.93% 3.91% 57.93% 9.3% 26.7% 42.5% 56.2%
Monday September 28th, 2015 40W, 3D 3.81% 61.79% 3.81% 61.79% 10% 28.2% 44.5% 58.5%
Tuesday September 29th, 2015 40W, 4D 3.68% 65.54% 3.68% 65.54% 10.7% 29.8% 46.6% 60.6%
Wednesday September 30th, 2015 40W, 5D 3.52% 69.15% 3.52% 69.15% 11.4% 31.3% 48.6% 62.7%
Thursday October 1st, 2015 40W, 6D 3.33% 72.57% 3.33% 72.57% 12.1% 32.9% 50.5% 64.7%
Friday October 2nd, 2015 41W, 0D 3.12% 75.8% 3.12% 75.8% 12.9% 34.4% 52.4% 66.6%
Saturday October 3rd, 2015 41W, 1D 2.9% 78.81% 2.9% 78.81% 13.7% 36% 54.3% 68.5%
Sunday October 4th, 2015 41W, 2D 2.66% 81.59% 2.66% 81.59% 14.4% 37.5% 56.1% 70.2%
Monday October 5th, 2015 41W, 3D 2.42% 84.13% 2.42% 84.13% 15.2% 39% 57.9% 71.9%
Tuesday October 6th, 2015 41W, 4D 2.18% 86.43% 2.18% 86.43% 16.1% 40.5% 59.6% 73.5%
Wednesday October 7th, 2015 41W, 5D 1.94% 88.49% 1.94% 88.49% 16.9% 42% 61.3% 75.1%
Thursday October 8th, 2015 41W, 6D 1.71% 90.32% 1.71% 90.32% 17.7% 43.4% 62.9% 76.4%
Friday October 9th, 2015 42W, 0D 1.5% 91.92% 1.5% 91.92% 18.6% 44.8% 64.5% 77.8%
Saturday October 10th, 2015 42W, 1D 1.3% 93.32% 1.3% 93.32% 19.5% 46.3% 65.9% 79.2%
Sunday October 11th, 2015 42W, 2D 1.11% 94.52% 1.11% 94.52% 20.3% 47.6% 67.3% 80.5%
Monday October 12th, 2015 42W, 3D 0.94% 95.54% 0.94% 95.54% 21.1% 48.9% 68.8% 81.6%
Tuesday October 13th, 2015 42W, 4D 0.79% 96.41% 0.79% 96.41% 22% 50.1% 70.2% 82.7%
Wednesday October 14th, 2015 42W, 5D 0.66% 97.13% 0.66% 97.13% 23% 51.6% 71.4% 83.6%
Thursday October 15th, 2015 42W, 6D 0.54% 97.72% 0.54% 97.72% 23.7% 53.1% 72.8% 84.6%
Friday October 16th, 2015 43W, 0D 0.44% 98.21% 0.44% 98.21% 24.6% 54.2% 73.7% 85.5%
Saturday October 17th, 2015 43W, 1D 0.35% 98.61% 0.35% 98.61% 25.2% 55.4% 74.8% 86.3%
Sunday October 18th, 2015 43W, 2D 0.28% 98.93% 0.28% 98.93% 26.2% 56.1% 75.7% 87.9%
Monday October 19th, 2015 43W, 3D 0.22% 99.18% 0.22% 99.18% 26.8% 57.3% 76.8% -%
Tuesday October 20th, 2015 43W, 4D 0.18% 99.38% 0.18% 99.38% 29% 58.1% 79% -%
Wednesday October 21st, 2015 43W, 5D 0.14% 99.53% 0.14% 99.53% 29.8% 59.6% -% -%
Thursday October 22nd, 2015 43W, 6D 0.1% 99.65% 0.1% 99.65% 28.6% 62.9% -% -%
Friday October 23rd, 2015 44W, 0D 0.08% 99.74% 0.08% 99.74% 30.8% -% -% -%
Saturday October 24th, 2015 44W, 1D 0.06% 99.81% 0.06% 99.81% 31.6% -% -% -%
Sunday October 25th, 2015 44W, 2D 0.04% 99.87% 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.

Bilingual Babies

Fri Mar 27 2:18 AM by Nae in Pregnancy & Parenting

As someone who only knows English, I am so impressed by people who are bilingual, trilingual, or multilingual. Only knowing English feels like you can only understand part of the world. The problem I've had is I don't really know what language I should try to learn.

I think it's a wonderful thing to be able to teach a child two languages. The part others have raised about being able to communicate with family members makes it that much more rewarding.

Don't worry about the naysayers - they always have to pick on something, and if it wasn't that, they'd just find something else. ;)


How Good Parents Miss Child Sexual Abuse and 5 Questions to Change That

Tue Mar 24 3:20 AM by rowan in Pregnancy & Parenting

And that includes parents too - I try to always ask "can I have a hug/kiss" rather than "give me a hug/kiss" and that she can always always say no if she doesn't want to, even with me. (She's old enough now that I've had enough practice that even writing "give me a hug" sounds weird to me)

Also I think on a more general level it's good to practice asking these kinds of questions anyway. Not just for abuse, but in general if you want to know what's going on in their life. Asking "how was school" gets an "I dunno" even now, but asking more specific things like "What was something funny that happened today" or "What did you do at recess?" really gets her talking more. Not sure where I read that, but the kinds of questions above made me think that sometimes just asking a better question will help get at what you want to know more than asking generalities.

The other thing is definitely definitely not making judgment on those things that they're saying. Instead try "What did you think about that ?" or "What did you do when happened?" "What would make you feel safe?" "What could you try if that happens again?" "Is there anything you'd like me to do?" These are things that I've asked wrt other kids on the playground (pushing etc) but I think it's the same idea in terms of empowering the child to talk about things that happen and letting them help come to the conclusions. Which isn't to say you can't help them get there by suggesting actions they could do, etc, just that if you get them talking about things that happen on a daily basis then if something weird happens then they'll likely be more comfortable telling you, especially if you've already shown them what boundaries there are and respecting those boundaries (like not tickling if they say they don't want to be tickled etc).


How did you decide how many kids to have?

Fri Feb 27 2:42 AM by MFS in Pregnancy & Parenting

First 2 were on purpose, 3rd kinda not so much, 4th was totally an oops (when you think things are broken, they have this habit of fixing themselves). Made sure we were done after that. Aside from that, we knew we'd have at least 2, likely 3, but the timing was not at all what we thought we were "planning". Such is life.


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."


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


Interacting with parents whose choices you don't trust

Thu Mar 26 3:08 PM by rowan in Pregnancy & Parenting

How can you tell who has been vaccinated or not?
That's the tricky part, you can't really. So unless the parents say something you never actually know.


It takes 13 million calories to raise a child!

Sun Mar 15 6:33 PM by Metcodon1 in Pregnancy & Parenting

Child care is BEYOND insanely expensive... When my husband and I were deciding to to have children we agreed to both go part time (4 days a week) in order to make our lives easier (we both make more than we would pay for day care, so we did take a financial hit with this decision). For example, whoever is home on a given day can throw in some laundry, or some food into the slow cooker, run errands... All of these things multiply in number once you have kids at the same time becoming more difficult to schedule. Unfortunately, when my daughter was around 1 my work situation changed and I had to go full time... let me tell you, it was definitely easier when I wasn't.

Anyway, the point I am getting to here is, when kids are little they require a lot of attention and sometimes (often?) some career sacrifice but it's TEMPORARY. When we decided to get pregnant we agreed that we would both slow down career wise for 5 years. For us it means, we do our jobs, we come home. We don't sign up for extra projects, we try to limit our travel, but it's all just for now. We also decided to have our kids close together for that reason (they'll be 2 years apart). Anyway, it's something to keep in mind. An 8 year old goes to school and doesn't need constant monitoring to keep from killing him/herself. It's ok to decide to slow down for a period of time, knowing that you'll come roaring back once they're older.


Bonding

Fri Feb 6 4:35 AM by Zeph in Pregnancy & Parenting

Bonding with my future infant is a concern of mine, because my depression is debilitating. I'm relieved to know that normally functioning women don't feel that head-over-heels mushy baby love.


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.


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.


Tips and pitfalls for gender-neutral parenting

Thu Mar 26 10:17 AM by Nae in Pregnancy & Parenting

I'm a while off having kids, but everything is so pervasively gendered I've had these concerns too.

Kids will learn a lot from what their parents do rather than say, so the most important thing you can do is just to be a good parent who believes in equality.

Media will be yelling at them their whole lives that they should conform and buy their products etc., so a healthy dose of cynicism could be learnt to.

You could try bringing it up with your kids to challenge them; "But why does he say that toy isn't for boys?".


Breastfeeding & accoutrements thereof

Thu Mar 12 8:27 PM by Rgipson in Pregnancy & Parenting

It's okay to admit your happiness is worth more than the "good" that solely breastfeeding supplies.

I breastfed my first until 10 months. I fed/pumped thru many growth spurts or dips in supply. Who knows, right? Baby would cry and cry and I could tell there was no milk, but I persevered. The trickiest part was, she wouldn't nurse in a room where she could look around or hear sounds (I'm a SAHM), so I had to go in a dark room, turn the lights off, and use a white noise machine. EVERY TIME SHE FED FOR 10 MONTHS. Talk about being hamstrung. I tried on so many occasions to feed her in other places, only to have a baby scream, scream, scream, until we got back to the dark room.

I was sleep deprived, overstimulated from all that screaming (she had colic until 14 months), and I was depressed as all get out. When I finally stopped, I began to feel like myself again. I believe that just as some women feel euphoria from the let down - that glorious oxytocin rush - it negatively effected my brain chemistry. It contributed to a negative mental health spiral.


Because judging other parents is absurd.

Tue Feb 3 7:05 AM by Zeph in Pregnancy & Parenting

It's alright to discuss these topics, but there needs to be boundaries. I would use the following, personally:

1. Don't insert yourself into a stranger's situation or bring up the topic yourself to a stranger.
2. It's probably not your business if you're not a parent yourself.
3. Ask the person why they are making these choices, don't assume.
4. Try to end on a positive note.

I don't feel right bringing up to my sister that I don't agree that she spanks my nephew, but after being a teacher, I am pretty forgiving of parents' choices. It's the hardest role there is. Even though I want to raise my children on nutritious meals, cloth diapers, and museum passes, I know I'm going to slip up and give them fries, Huggies, and Disney DVD's.

I also feel that home birth is a fine option for low-risk births, where the mother is well coached and the midwife is reputable. If you live near a hospital and your midwife is highly qualified, why not? They have equipment. I won't be choosing this option, but with any birth plan there needs to be a series of precautions taken.


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/


some quotes recently I read

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

i search about these quotes in google