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 October 27th, 2022.
| 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 | ||
| Thursday September 22nd, 2022 | 35W, 0D | 0.01% | 0.02% | -% | -% | -% | 0.1% | 0.1% | 0.2% |
| Friday September 23rd, 2022 | 35W, 1D | 0.01% | 0.03% | -% | -% | -% | 0.1% | 0.2% | 0.3% |
| Saturday September 24th, 2022 | 35W, 2D | 0.02% | 0.05% | -% | -% | -% | 0.1% | 0.2% | 0.4% |
| Sunday September 25th, 2022 | 35W, 3D | 0.02% | 0.07% | -% | -% | -% | 0.1% | 0.3% | 0.6% |
| Monday September 26th, 2022 | 35W, 4D | 0.03% | 0.1% | -% | -% | -% | 0.2% | 0.4% | 0.7% |
| Tuesday September 27th, 2022 | 35W, 5D | 0.04% | 0.13% | -% | -% | -% | 0.2% | 0.5% | 0.9% |
| Wednesday September 28th, 2022 | 35W, 6D | 0.06% | 0.19% | -% | -% | 0.1% | 0.3% | 0.6% | 1.2% |
| Thursday September 29th, 2022 | 36W, 0D | 0.08% | 0.26% | -% | -% | 0.1% | 0.4% | 0.8% | 1.5% |
| Friday September 30th, 2022 | 36W, 1D | 0.1% | 0.35% | -% | -% | 0.1% | 0.5% | 1% | 1.9% |
| Saturday October 1st, 2022 | 36W, 2D | 0.14% | 0.47% | -% | -% | 0.1% | 0.6% | 1.3% | 2.4% |
| Sunday October 2nd, 2022 | 36W, 3D | 0.18% | 0.62% | -% | -% | 0.2% | 0.8% | 1.7% | 3% |
| Monday October 3rd, 2022 | 36W, 4D | 0.22% | 0.82% | -% | -% | 0.2% | 1% | 2.1% | 3.7% |
| Tuesday October 4th, 2022 | 36W, 5D | 0.28% | 1.07% | -% | -% | 0.3% | 1.2% | 2.5% | 4.5% |
| Wednesday October 5th, 2022 | 36W, 6D | 0.35% | 1.39% | -% | -% | 0.4% | 1.5% | 3.1% | 5.4% |
| Thursday October 6th, 2022 | 37W, 0D | 0.44% | 1.79% | -% | -% | 0.4% | 1.8% | 3.8% | 6.4% |
| Friday October 7th, 2022 | 37W, 1D | 0.54% | 2.28% | -% | -% | 0.6% | 2.2% | 4.5% | 7.6% |
| Saturday October 8th, 2022 | 37W, 2D | 0.66% | 2.87% | -% | -% | 0.7% | 2.7% | 5.4% | 8.9% |
| Sunday October 9th, 2022 | 37W, 3D | 0.79% | 3.59% | -% | -% | 0.8% | 3.2% | 6.3% | 10.4% |
| Monday October 10th, 2022 | 37W, 4D | 0.94% | 4.46% | -% | -% | 1% | 3.8% | 7.4% | 11.9% |
| Tuesday October 11th, 2022 | 37W, 5D | 1.11% | 5.48% | -% | -% | 1.2% | 4.4% | 8.6% | 13.7% |
| Wednesday October 12th, 2022 | 37W, 6D | 1.3% | 6.68% | -% | -% | 1.4% | 5.2% | 9.8% | 15.5% |
| Thursday October 13th, 2022 | 38W, 0D | 1.5% | 8.08% | -% | -% | 1.6% | 6% | 11.2% | 17.5% |
| Friday October 14th, 2022 | 38W, 1D | 1.71% | 9.68% | -% | -% | 1.9% | 6.9% | 12.7% | 19.7% |
| Saturday October 15th, 2022 | 38W, 2D | 1.94% | 11.51% | -% | -% | 2.2% | 7.8% | 14.3% | 21.9% |
| Sunday October 16th, 2022 | 38W, 3D | 2.18% | 13.57% | -% | -% | 2.5% | 8.8% | 16% | 24.2% |
| Monday October 17th, 2022 | 38W, 4D | 2.42% | 15.87% | -% | -% | 2.9% | 9.9% | 17.8% | 26.6% |
| Tuesday October 18th, 2022 | 38W, 5D | 2.66% | 18.41% | -% | -% | 3.3% | 11.1% | 19.7% | 29% |
| Wednesday October 19th, 2022 | 38W, 6D | 2.9% | 21.19% | -% | -% | 3.7% | 12.3% | 21.6% | 31.5% |
| Thursday October 20th, 2022 | 39W, 0D | 3.12% | 24.2% | -% | -% | 4.1% | 13.5% | 23.6% | 34% |
| Friday October 21st, 2022 | 39W, 1D | 3.33% | 27.43% | -% | -% | 4.6% | 14.9% | 25.6% | 36.6% |
| Saturday October 22nd, 2022 | 39W, 2D | 3.52% | 30.85% | -% | -% | 5.1% | 16.2% | 27.7% | 39.2% |
| Sunday October 23rd, 2022 | 39W, 3D | 3.68% | 34.46% | -% | -% | 5.6% | 17.6% | 29.8% | 41.7% |
| Monday October 24th, 2022 | 39W, 4D | 3.81% | 38.21% | -% | -% | 6.2% | 19.1% | 31.9% | 44.2% |
| Tuesday October 25th, 2022 | 39W, 5D | 3.91% | 42.07% | -% | -% | 6.7% | 20.6% | 34% | 46.7% |
| Wednesday October 26th, 2022 | 39W, 6D | 3.97% | 46.02% | -% | -% | 7.4% | 22.1% | 36.2% | 49.2% |
| Thursday October 27th, 2022 | 40W, 0D | 3.99% | 50% | -% | -% | 8% | 23.6% | 38.3% | 51.6% |
| Friday October 28th, 2022 | 40W, 1D | 3.97% | 53.98% | -% | -% | 8.6% | 25.1% | 40.4% | 54% |
| Saturday October 29th, 2022 | 40W, 2D | 3.91% | 57.93% | -% | -% | 9.3% | 26.7% | 42.5% | 56.2% |
| Sunday October 30th, 2022 | 40W, 3D | 3.81% | 61.79% | -% | -% | 10% | 28.2% | 44.5% | 58.5% |
| Monday October 31st, 2022 | 40W, 4D | 3.68% | 65.54% | -% | -% | 10.7% | 29.8% | 46.6% | 60.6% |
| Tuesday November 1st, 2022 | 40W, 5D | 3.52% | 69.15% | -% | -% | 11.4% | 31.3% | 48.6% | 62.7% |
| Wednesday November 2nd, 2022 | 40W, 6D | 3.33% | 72.57% | -% | -% | 12.1% | 32.9% | 50.5% | 64.7% |
| Thursday November 3rd, 2022 | 41W, 0D | 3.12% | 75.8% | -% | -% | 12.9% | 34.4% | 52.4% | 66.6% |
| Friday November 4th, 2022 | 41W, 1D | 2.9% | 78.81% | -% | -% | 13.7% | 36% | 54.3% | 68.5% |
| Saturday November 5th, 2022 | 41W, 2D | 2.66% | 81.59% | -% | -% | 14.4% | 37.5% | 56.1% | 70.2% |
| Sunday November 6th, 2022 | 41W, 3D | 2.42% | 84.13% | -% | -% | 15.2% | 39% | 57.9% | 71.9% |
| Monday November 7th, 2022 | 41W, 4D | 2.18% | 86.43% | -% | -% | 16.1% | 40.5% | 59.6% | 73.5% |
| Tuesday November 8th, 2022 | 41W, 5D | 1.94% | 88.49% | -% | -% | 16.9% | 42% | 61.3% | 75.1% |
| Wednesday November 9th, 2022 | 41W, 6D | 1.71% | 90.32% | -% | -% | 17.7% | 43.4% | 62.9% | 76.4% |
| Thursday November 10th, 2022 | 42W, 0D | 1.5% | 91.92% | -% | -% | 18.6% | 44.8% | 64.5% | 77.8% |
| Friday November 11th, 2022 | 42W, 1D | 1.3% | 93.32% | -% | -% | 19.5% | 46.3% | 65.9% | 79.2% |
| Saturday November 12th, 2022 | 42W, 2D | 1.11% | 94.52% | -% | -% | 20.3% | 47.6% | 67.3% | 80.5% |
| Sunday November 13th, 2022 | 42W, 3D | 0.94% | 95.54% | -% | -% | 21.1% | 48.9% | 68.8% | 81.6% |
| Monday November 14th, 2022 | 42W, 4D | 0.79% | 96.41% | -% | -% | 22% | 50.1% | 70.2% | 82.7% |
| Tuesday November 15th, 2022 | 42W, 5D | 0.66% | 97.13% | -% | -% | 23% | 51.6% | 71.4% | 83.6% |
| Wednesday November 16th, 2022 | 42W, 6D | 0.54% | 97.72% | -% | -% | 23.7% | 53.1% | 72.8% | 84.6% |
| Thursday November 17th, 2022 | 43W, 0D | 0.44% | 98.21% | -% | -% | 24.6% | 54.2% | 73.7% | 85.5% |
| Friday November 18th, 2022 | 43W, 1D | 0.35% | 98.61% | -% | -% | 25.2% | 55.4% | 74.8% | 86.3% |
| Saturday November 19th, 2022 | 43W, 2D | 0.28% | 98.93% | -% | -% | 26.2% | 56.1% | 75.7% | 87.9% |
| Sunday November 20th, 2022 | 43W, 3D | 0.22% | 99.18% | -% | -% | 26.8% | 57.3% | 76.8% | -% |
| Monday November 21st, 2022 | 43W, 4D | 0.18% | 99.38% | -% | -% | 29% | 58.1% | 79% | -% |
| Tuesday November 22nd, 2022 | 43W, 5D | 0.14% | 99.53% | -% | -% | 29.8% | 59.6% | -% | -% |
| Wednesday November 23rd, 2022 | 43W, 6D | 0.1% | 99.65% | -% | -% | 28.6% | 62.9% | -% | -% |
| Thursday November 24th, 2022 | 44W, 0D | 0.08% | 99.74% | -% | -% | 30.8% | -% | -% | -% |
| Friday November 25th, 2022 | 44W, 1D | 0.06% | 99.81% | -% | -% | 31.6% | -% | -% | -% |
| Saturday November 26th, 2022 | 44W, 2D | 0.04% | 99.87% | -% | -% | 30.8% | -% | -% | -% |
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.