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 May 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 | ||
| Friday April 22nd, 2022 | 35W, 0D | 0.01% | 0.02% | -% | -% | -% | 0.1% | 0.1% | 0.2% |
| Saturday April 23rd, 2022 | 35W, 1D | 0.01% | 0.03% | -% | -% | -% | 0.1% | 0.2% | 0.3% |
| Sunday April 24th, 2022 | 35W, 2D | 0.02% | 0.05% | -% | -% | -% | 0.1% | 0.2% | 0.4% |
| Monday April 25th, 2022 | 35W, 3D | 0.02% | 0.07% | -% | -% | -% | 0.1% | 0.3% | 0.6% |
| Tuesday April 26th, 2022 | 35W, 4D | 0.03% | 0.1% | -% | -% | -% | 0.2% | 0.4% | 0.7% |
| Wednesday April 27th, 2022 | 35W, 5D | 0.04% | 0.13% | -% | -% | -% | 0.2% | 0.5% | 0.9% |
| Thursday April 28th, 2022 | 35W, 6D | 0.06% | 0.19% | -% | -% | 0.1% | 0.3% | 0.6% | 1.2% |
| Friday April 29th, 2022 | 36W, 0D | 0.08% | 0.26% | -% | -% | 0.1% | 0.4% | 0.8% | 1.5% |
| Saturday April 30th, 2022 | 36W, 1D | 0.1% | 0.35% | -% | -% | 0.1% | 0.5% | 1% | 1.9% |
| Sunday May 1st, 2022 | 36W, 2D | 0.14% | 0.47% | -% | -% | 0.1% | 0.6% | 1.3% | 2.4% |
| Monday May 2nd, 2022 | 36W, 3D | 0.18% | 0.62% | -% | -% | 0.2% | 0.8% | 1.7% | 3% |
| Tuesday May 3rd, 2022 | 36W, 4D | 0.22% | 0.82% | -% | -% | 0.2% | 1% | 2.1% | 3.7% |
| Wednesday May 4th, 2022 | 36W, 5D | 0.28% | 1.07% | -% | -% | 0.3% | 1.2% | 2.5% | 4.5% |
| Thursday May 5th, 2022 | 36W, 6D | 0.35% | 1.39% | -% | -% | 0.4% | 1.5% | 3.1% | 5.4% |
| Friday May 6th, 2022 | 37W, 0D | 0.44% | 1.79% | -% | -% | 0.4% | 1.8% | 3.8% | 6.4% |
| Saturday May 7th, 2022 | 37W, 1D | 0.54% | 2.28% | -% | -% | 0.6% | 2.2% | 4.5% | 7.6% |
| Sunday May 8th, 2022 | 37W, 2D | 0.66% | 2.87% | -% | -% | 0.7% | 2.7% | 5.4% | 8.9% |
| Monday May 9th, 2022 | 37W, 3D | 0.79% | 3.59% | -% | -% | 0.8% | 3.2% | 6.3% | 10.4% |
| Tuesday May 10th, 2022 | 37W, 4D | 0.94% | 4.46% | -% | -% | 1% | 3.8% | 7.4% | 11.9% |
| Wednesday May 11th, 2022 | 37W, 5D | 1.11% | 5.48% | -% | -% | 1.2% | 4.4% | 8.6% | 13.7% |
| Thursday May 12th, 2022 | 37W, 6D | 1.3% | 6.68% | -% | -% | 1.4% | 5.2% | 9.8% | 15.5% |
| Friday May 13th, 2022 | 38W, 0D | 1.5% | 8.08% | -% | -% | 1.6% | 6% | 11.2% | 17.5% |
| Saturday May 14th, 2022 | 38W, 1D | 1.71% | 9.68% | -% | -% | 1.9% | 6.9% | 12.7% | 19.7% |
| Sunday May 15th, 2022 | 38W, 2D | 1.94% | 11.51% | -% | -% | 2.2% | 7.8% | 14.3% | 21.9% |
| Monday May 16th, 2022 | 38W, 3D | 2.18% | 13.57% | -% | -% | 2.5% | 8.8% | 16% | 24.2% |
| Tuesday May 17th, 2022 | 38W, 4D | 2.42% | 15.87% | -% | -% | 2.9% | 9.9% | 17.8% | 26.6% |
| Wednesday May 18th, 2022 | 38W, 5D | 2.66% | 18.41% | -% | -% | 3.3% | 11.1% | 19.7% | 29% |
| Thursday May 19th, 2022 | 38W, 6D | 2.9% | 21.19% | -% | -% | 3.7% | 12.3% | 21.6% | 31.5% |
| Friday May 20th, 2022 | 39W, 0D | 3.12% | 24.2% | -% | -% | 4.1% | 13.5% | 23.6% | 34% |
| Saturday May 21st, 2022 | 39W, 1D | 3.33% | 27.43% | -% | -% | 4.6% | 14.9% | 25.6% | 36.6% |
| Sunday May 22nd, 2022 | 39W, 2D | 3.52% | 30.85% | -% | -% | 5.1% | 16.2% | 27.7% | 39.2% |
| Monday May 23rd, 2022 | 39W, 3D | 3.68% | 34.46% | -% | -% | 5.6% | 17.6% | 29.8% | 41.7% |
| Tuesday May 24th, 2022 | 39W, 4D | 3.81% | 38.21% | -% | -% | 6.2% | 19.1% | 31.9% | 44.2% |
| Wednesday May 25th, 2022 | 39W, 5D | 3.91% | 42.07% | -% | -% | 6.7% | 20.6% | 34% | 46.7% |
| Thursday May 26th, 2022 | 39W, 6D | 3.97% | 46.02% | -% | -% | 7.4% | 22.1% | 36.2% | 49.2% |
| Friday May 27th, 2022 | 40W, 0D | 3.99% | 50% | 8% | 0% | 8% | 23.6% | 38.3% | 51.6% |
| Saturday May 28th, 2022 | 40W, 1D | 3.97% | 53.98% | 7.9% | 8% | 8.6% | 25.1% | 40.4% | 54% |
| Sunday May 29th, 2022 | 40W, 2D | 3.91% | 57.93% | 7.8% | 15.9% | 9.3% | 26.7% | 42.5% | 56.2% |
| Monday May 30th, 2022 | 40W, 3D | 3.81% | 61.79% | 7.6% | 23.6% | 10% | 28.2% | 44.5% | 58.5% |
| Tuesday May 31st, 2022 | 40W, 4D | 3.68% | 65.54% | 7.4% | 31.1% | 10.7% | 29.8% | 46.6% | 60.6% |
| Wednesday June 1st, 2022 | 40W, 5D | 3.52% | 69.15% | 7% | 38.3% | 11.4% | 31.3% | 48.6% | 62.7% |
| Thursday June 2nd, 2022 | 40W, 6D | 3.33% | 72.57% | 6.7% | 45.1% | 12.1% | 32.9% | 50.5% | 64.7% |
| Friday June 3rd, 2022 | 41W, 0D | 3.12% | 75.8% | 6.2% | 51.6% | 12.9% | 34.4% | 52.4% | 66.6% |
| Saturday June 4th, 2022 | 41W, 1D | 2.9% | 78.81% | 5.8% | 57.6% | 13.7% | 36% | 54.3% | 68.5% |
| Sunday June 5th, 2022 | 41W, 2D | 2.66% | 81.59% | 5.3% | 63.2% | 14.4% | 37.5% | 56.1% | 70.2% |
| Monday June 6th, 2022 | 41W, 3D | 2.42% | 84.13% | 4.8% | 68.3% | 15.2% | 39% | 57.9% | 71.9% |
| Tuesday June 7th, 2022 | 41W, 4D | 2.18% | 86.43% | 4.4% | 72.9% | 16.1% | 40.5% | 59.6% | 73.5% |
| Wednesday June 8th, 2022 | 41W, 5D | 1.94% | 88.49% | 3.9% | 77% | 16.9% | 42% | 61.3% | 75.1% |
| Thursday June 9th, 2022 | 41W, 6D | 1.71% | 90.32% | 3.4% | 80.6% | 17.7% | 43.4% | 62.9% | 76.4% |
| Friday June 10th, 2022 | 42W, 0D | 1.5% | 91.92% | 3% | 83.8% | 18.6% | 44.8% | 64.5% | 77.8% |
| Saturday June 11th, 2022 | 42W, 1D | 1.3% | 93.32% | 2.6% | 86.6% | 19.5% | 46.3% | 65.9% | 79.2% |
| Sunday June 12th, 2022 | 42W, 2D | 1.11% | 94.52% | 2.2% | 89% | 20.3% | 47.6% | 67.3% | 80.5% |
| Monday June 13th, 2022 | 42W, 3D | 0.94% | 95.54% | 1.9% | 91.1% | 21.1% | 48.9% | 68.8% | 81.6% |
| Tuesday June 14th, 2022 | 42W, 4D | 0.79% | 96.41% | 1.6% | 92.8% | 22% | 50.1% | 70.2% | 82.7% |
| Wednesday June 15th, 2022 | 42W, 5D | 0.66% | 97.13% | 1.3% | 94.3% | 23% | 51.6% | 71.4% | 83.6% |
| Thursday June 16th, 2022 | 42W, 6D | 0.54% | 97.72% | 1.1% | 95.4% | 23.7% | 53.1% | 72.8% | 84.6% |
| Friday June 17th, 2022 | 43W, 0D | 0.44% | 98.21% | 0.9% | 96.4% | 24.6% | 54.2% | 73.7% | 85.5% |
| Saturday June 18th, 2022 | 43W, 1D | 0.35% | 98.61% | 0.7% | 97.2% | 25.2% | 55.4% | 74.8% | 86.3% |
| Sunday June 19th, 2022 | 43W, 2D | 0.28% | 98.93% | 0.6% | 97.9% | 26.2% | 56.1% | 75.7% | 87.9% |
| Monday June 20th, 2022 | 43W, 3D | 0.22% | 99.18% | 0.4% | 98.4% | 26.8% | 57.3% | 76.8% | -% |
| Tuesday June 21st, 2022 | 43W, 4D | 0.18% | 99.38% | 0.4% | 98.8% | 29% | 58.1% | 79% | -% |
| Wednesday June 22nd, 2022 | 43W, 5D | 0.14% | 99.53% | 0.3% | 99.1% | 29.8% | 59.6% | -% | -% |
| Thursday June 23rd, 2022 | 43W, 6D | 0.1% | 99.65% | 0.2% | 99.3% | 28.6% | 62.9% | -% | -% |
| Friday June 24th, 2022 | 44W, 0D | 0.08% | 99.74% | 0.2% | 99.5% | 30.8% | -% | -% | -% |
| Saturday June 25th, 2022 | 44W, 1D | 0.06% | 99.81% | 0.1% | 99.6% | 31.6% | -% | -% | -% |
| Sunday June 26th, 2022 | 44W, 2D | 0.04% | 99.87% | 0.1% | 99.7% | 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.