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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 March 31st, 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
Tuesday February 24th, 2015 35W, 0D 0.01% 0.02% -% -% -% 0.1% 0.1% 0.2%
Wednesday February 25th, 2015 35W, 1D 0.01% 0.03% -% -% -% 0.1% 0.2% 0.3%
Thursday February 26th, 2015 35W, 2D 0.02% 0.05% -% -% -% 0.1% 0.2% 0.4%
Friday February 27th, 2015 35W, 3D 0.02% 0.07% -% -% -% 0.1% 0.3% 0.6%
Saturday February 28th, 2015 35W, 4D 0.03% 0.1% -% -% -% 0.2% 0.4% 0.7%
Sunday March 1st, 2015 35W, 5D 0.04% 0.13% -% -% -% 0.2% 0.5% 0.9%
Monday March 2nd, 2015 35W, 6D 0.06% 0.19% -% -% 0.1% 0.3% 0.6% 1.2%
Tuesday March 3rd, 2015 36W, 0D 0.08% 0.26% -% -% 0.1% 0.4% 0.8% 1.5%
Wednesday March 4th, 2015 36W, 1D 0.1% 0.35% -% -% 0.1% 0.5% 1% 1.9%
Thursday March 5th, 2015 36W, 2D 0.14% 0.47% -% -% 0.1% 0.6% 1.3% 2.4%
Friday March 6th, 2015 36W, 3D 0.18% 0.62% -% -% 0.2% 0.8% 1.7% 3%
Saturday March 7th, 2015 36W, 4D 0.22% 0.82% -% -% 0.2% 1% 2.1% 3.7%
Sunday March 8th, 2015 36W, 5D 0.28% 1.07% -% -% 0.3% 1.2% 2.5% 4.5%
Monday March 9th, 2015 36W, 6D 0.35% 1.39% -% -% 0.4% 1.5% 3.1% 5.4%
Tuesday March 10th, 2015 37W, 0D 0.44% 1.79% -% -% 0.4% 1.8% 3.8% 6.4%
Wednesday March 11th, 2015 37W, 1D 0.54% 2.28% -% -% 0.6% 2.2% 4.5% 7.6%
Thursday March 12th, 2015 37W, 2D 0.66% 2.87% -% -% 0.7% 2.7% 5.4% 8.9%
Friday March 13th, 2015 37W, 3D 0.79% 3.59% -% -% 0.8% 3.2% 6.3% 10.4%
Saturday March 14th, 2015 37W, 4D 0.94% 4.46% -% -% 1% 3.8% 7.4% 11.9%
Sunday March 15th, 2015 37W, 5D 1.11% 5.48% -% -% 1.2% 4.4% 8.6% 13.7%
Monday March 16th, 2015 37W, 6D 1.3% 6.68% -% -% 1.4% 5.2% 9.8% 15.5%
Tuesday March 17th, 2015 38W, 0D 1.5% 8.08% -% -% 1.6% 6% 11.2% 17.5%
Wednesday March 18th, 2015 38W, 1D 1.71% 9.68% -% -% 1.9% 6.9% 12.7% 19.7%
Thursday March 19th, 2015 38W, 2D 1.94% 11.51% -% -% 2.2% 7.8% 14.3% 21.9%
Friday March 20th, 2015 38W, 3D 2.18% 13.57% -% -% 2.5% 8.8% 16% 24.2%
Saturday March 21st, 2015 38W, 4D 2.42% 15.87% -% -% 2.9% 9.9% 17.8% 26.6%
Sunday March 22nd, 2015 38W, 5D 2.66% 18.41% -% -% 3.3% 11.1% 19.7% 29%
Monday March 23rd, 2015 38W, 6D 2.9% 21.19% -% -% 3.7% 12.3% 21.6% 31.5%
Tuesday March 24th, 2015 39W, 0D 3.12% 24.2% -% -% 4.1% 13.5% 23.6% 34%
Wednesday March 25th, 2015 39W, 1D 3.33% 27.43% -% -% 4.6% 14.9% 25.6% 36.6%
Thursday March 26th, 2015 39W, 2D 3.52% 30.85% -% -% 5.1% 16.2% 27.7% 39.2%
Friday March 27th, 2015 39W, 3D 3.68% 34.46% -% -% 5.6% 17.6% 29.8% 41.7%
Saturday March 28th, 2015 39W, 4D 3.81% 38.21% -% -% 6.2% 19.1% 31.9% 44.2%
Sunday March 29th, 2015 39W, 5D 3.91% 42.07% -% -% 6.7% 20.6% 34% 46.7%
Monday March 30th, 2015 39W, 6D 3.97% 46.02% -% -% 7.4% 22.1% 36.2% 49.2%
Tuesday March 31st, 2015 40W, 0D 3.99% 50% -% -% 8% 23.6% 38.3% 51.6%
Wednesday April 1st, 2015 40W, 1D 3.97% 53.98% 7.9% 8% 8.6% 25.1% 40.4% 54%
Thursday April 2nd, 2015 40W, 2D 3.91% 57.93% 7.8% 15.9% 9.3% 26.7% 42.5% 56.2%
Friday April 3rd, 2015 40W, 3D 3.81% 61.79% 7.6% 23.6% 10% 28.2% 44.5% 58.5%
Saturday April 4th, 2015 40W, 4D 3.68% 65.54% 7.4% 31.1% 10.7% 29.8% 46.6% 60.6%
Sunday April 5th, 2015 40W, 5D 3.52% 69.15% 7% 38.3% 11.4% 31.3% 48.6% 62.7%
Monday April 6th, 2015 40W, 6D 3.33% 72.57% 6.7% 45.1% 12.1% 32.9% 50.5% 64.7%
Tuesday April 7th, 2015 41W, 0D 3.12% 75.8% 6.2% 51.6% 12.9% 34.4% 52.4% 66.6%
Wednesday April 8th, 2015 41W, 1D 2.9% 78.81% 5.8% 57.6% 13.7% 36% 54.3% 68.5%
Thursday April 9th, 2015 41W, 2D 2.66% 81.59% 5.3% 63.2% 14.4% 37.5% 56.1% 70.2%
Friday April 10th, 2015 41W, 3D 2.42% 84.13% 4.8% 68.3% 15.2% 39% 57.9% 71.9%
Saturday April 11th, 2015 41W, 4D 2.18% 86.43% 4.4% 72.9% 16.1% 40.5% 59.6% 73.5%
Sunday April 12th, 2015 41W, 5D 1.94% 88.49% 3.9% 77% 16.9% 42% 61.3% 75.1%
Monday April 13th, 2015 41W, 6D 1.71% 90.32% 3.4% 80.6% 17.7% 43.4% 62.9% 76.4%
Tuesday April 14th, 2015 42W, 0D 1.5% 91.92% 3% 83.8% 18.6% 44.8% 64.5% 77.8%
Wednesday April 15th, 2015 42W, 1D 1.3% 93.32% 2.6% 86.6% 19.5% 46.3% 65.9% 79.2%
Thursday April 16th, 2015 42W, 2D 1.11% 94.52% 2.2% 89% 20.3% 47.6% 67.3% 80.5%
Friday April 17th, 2015 42W, 3D 0.94% 95.54% 1.9% 91.1% 21.1% 48.9% 68.8% 81.6%
Saturday April 18th, 2015 42W, 4D 0.79% 96.41% 1.6% 92.8% 22% 50.1% 70.2% 82.7%
Sunday April 19th, 2015 42W, 5D 0.66% 97.13% 1.3% 94.3% 23% 51.6% 71.4% 83.6%
Monday April 20th, 2015 42W, 6D 0.54% 97.72% 1.1% 95.4% 23.7% 53.1% 72.8% 84.6%
Tuesday April 21st, 2015 43W, 0D 0.44% 98.21% 0.9% 96.4% 24.6% 54.2% 73.7% 85.5%
Wednesday April 22nd, 2015 43W, 1D 0.35% 98.61% 0.7% 97.2% 25.2% 55.4% 74.8% 86.3%
Thursday April 23rd, 2015 43W, 2D 0.28% 98.93% 0.6% 97.9% 26.2% 56.1% 75.7% 87.9%
Friday April 24th, 2015 43W, 3D 0.22% 99.18% 0.4% 98.4% 26.8% 57.3% 76.8% -%
Saturday April 25th, 2015 43W, 4D 0.18% 99.38% 0.4% 98.8% 29% 58.1% 79% -%
Sunday April 26th, 2015 43W, 5D 0.14% 99.53% 0.3% 99.1% 29.8% 59.6% -% -%
Monday April 27th, 2015 43W, 6D 0.1% 99.65% 0.2% 99.3% 28.6% 62.9% -% -%
Tuesday April 28th, 2015 44W, 0D 0.08% 99.74% 0.2% 99.5% 30.8% -% -% -%
Wednesday April 29th, 2015 44W, 1D 0.06% 99.81% 0.1% 99.6% 31.6% -% -% -%
Thursday April 30th, 2015 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.

Tips and pitfalls for gender-neutral parenting

Mon Mar 30 9:25 PM by rowan in Pregnancy & Parenting

^I agree with that! :)

Part of "gender neutral" parenting is supplying the side of things that doesn't get given by other people.


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. ;)


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.


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/


The responsibility of choosing a name

Mon Mar 30 9:24 PM by rowan in Pregnancy & Parenting

Good luck! We had a list of names (both boy and girl since we didn't know) and it all worked out. In the end just remember if you wind up hating it or it doesn't fit you can always change it. :) People do this! :) It'll be fine!


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.


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


Advice for non-parents?

Mon Mar 30 3:18 AM by Zeph in Pregnancy & Parenting

I'd advise against giving clothes. Not only does it eliminate the need to choose colors, but most parents get enough baby clothes.

At baby showers, I always give gifts for the mom (lotion, foot bath, etc.) and medical supplies for the baby (like snot suckers). Diapers in the bigger sizes for when the baby is older, too. Don't forget to throw in 6-12 month baby supplies.


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).


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.