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 30th, 2020.
| 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 | ||
| Saturday April 25th, 2020 | 35W, 0D | 0.01% | 0.02% | -% | -% | -% | 0.1% | 0.1% | 0.2% |
| Sunday April 26th, 2020 | 35W, 1D | 0.01% | 0.03% | -% | -% | -% | 0.1% | 0.2% | 0.3% |
| Monday April 27th, 2020 | 35W, 2D | 0.02% | 0.05% | -% | -% | -% | 0.1% | 0.2% | 0.4% |
| Tuesday April 28th, 2020 | 35W, 3D | 0.02% | 0.07% | -% | -% | -% | 0.1% | 0.3% | 0.6% |
| Wednesday April 29th, 2020 | 35W, 4D | 0.03% | 0.1% | -% | -% | -% | 0.2% | 0.4% | 0.7% |
| Thursday April 30th, 2020 | 35W, 5D | 0.04% | 0.13% | -% | -% | -% | 0.2% | 0.5% | 0.9% |
| Friday May 1st, 2020 | 35W, 6D | 0.06% | 0.19% | -% | -% | 0.1% | 0.3% | 0.6% | 1.2% |
| Saturday May 2nd, 2020 | 36W, 0D | 0.08% | 0.26% | -% | -% | 0.1% | 0.4% | 0.8% | 1.5% |
| Sunday May 3rd, 2020 | 36W, 1D | 0.1% | 0.35% | -% | -% | 0.1% | 0.5% | 1% | 1.9% |
| Monday May 4th, 2020 | 36W, 2D | 0.14% | 0.47% | -% | -% | 0.1% | 0.6% | 1.3% | 2.4% |
| Tuesday May 5th, 2020 | 36W, 3D | 0.18% | 0.62% | -% | -% | 0.2% | 0.8% | 1.7% | 3% |
| Wednesday May 6th, 2020 | 36W, 4D | 0.22% | 0.82% | -% | -% | 0.2% | 1% | 2.1% | 3.7% |
| Thursday May 7th, 2020 | 36W, 5D | 0.28% | 1.07% | -% | -% | 0.3% | 1.2% | 2.5% | 4.5% |
| Friday May 8th, 2020 | 36W, 6D | 0.35% | 1.39% | -% | -% | 0.4% | 1.5% | 3.1% | 5.4% |
| Saturday May 9th, 2020 | 37W, 0D | 0.44% | 1.79% | -% | -% | 0.4% | 1.8% | 3.8% | 6.4% |
| Sunday May 10th, 2020 | 37W, 1D | 0.54% | 2.28% | -% | -% | 0.6% | 2.2% | 4.5% | 7.6% |
| Monday May 11th, 2020 | 37W, 2D | 0.66% | 2.87% | -% | -% | 0.7% | 2.7% | 5.4% | 8.9% |
| Tuesday May 12th, 2020 | 37W, 3D | 0.79% | 3.59% | -% | -% | 0.8% | 3.2% | 6.3% | 10.4% |
| Wednesday May 13th, 2020 | 37W, 4D | 0.94% | 4.46% | -% | -% | 1% | 3.8% | 7.4% | 11.9% |
| Thursday May 14th, 2020 | 37W, 5D | 1.11% | 5.48% | -% | -% | 1.2% | 4.4% | 8.6% | 13.7% |
| Friday May 15th, 2020 | 37W, 6D | 1.3% | 6.68% | -% | -% | 1.4% | 5.2% | 9.8% | 15.5% |
| Saturday May 16th, 2020 | 38W, 0D | 1.5% | 8.08% | -% | -% | 1.6% | 6% | 11.2% | 17.5% |
| Sunday May 17th, 2020 | 38W, 1D | 1.71% | 9.68% | -% | -% | 1.9% | 6.9% | 12.7% | 19.7% |
| Monday May 18th, 2020 | 38W, 2D | 1.94% | 11.51% | -% | -% | 2.2% | 7.8% | 14.3% | 21.9% |
| Tuesday May 19th, 2020 | 38W, 3D | 2.18% | 13.57% | -% | -% | 2.5% | 8.8% | 16% | 24.2% |
| Wednesday May 20th, 2020 | 38W, 4D | 2.42% | 15.87% | -% | -% | 2.9% | 9.9% | 17.8% | 26.6% |
| Thursday May 21st, 2020 | 38W, 5D | 2.66% | 18.41% | -% | -% | 3.3% | 11.1% | 19.7% | 29% |
| Friday May 22nd, 2020 | 38W, 6D | 2.9% | 21.19% | -% | -% | 3.7% | 12.3% | 21.6% | 31.5% |
| Saturday May 23rd, 2020 | 39W, 0D | 3.12% | 24.2% | -% | -% | 4.1% | 13.5% | 23.6% | 34% |
| Sunday May 24th, 2020 | 39W, 1D | 3.33% | 27.43% | -% | -% | 4.6% | 14.9% | 25.6% | 36.6% |
| Monday May 25th, 2020 | 39W, 2D | 3.52% | 30.85% | -% | -% | 5.1% | 16.2% | 27.7% | 39.2% |
| Tuesday May 26th, 2020 | 39W, 3D | 3.68% | 34.46% | -% | -% | 5.6% | 17.6% | 29.8% | 41.7% |
| Wednesday May 27th, 2020 | 39W, 4D | 3.81% | 38.21% | -% | -% | 6.2% | 19.1% | 31.9% | 44.2% |
| Thursday May 28th, 2020 | 39W, 5D | 3.91% | 42.07% | -% | -% | 6.7% | 20.6% | 34% | 46.7% |
| Friday May 29th, 2020 | 39W, 6D | 3.97% | 46.02% | -% | -% | 7.4% | 22.1% | 36.2% | 49.2% |
| Saturday May 30th, 2020 | 40W, 0D | 3.99% | 50% | 8% | 0% | 8% | 23.6% | 38.3% | 51.6% |
| Sunday May 31st, 2020 | 40W, 1D | 3.97% | 53.98% | 7.9% | 8% | 8.6% | 25.1% | 40.4% | 54% |
| Monday June 1st, 2020 | 40W, 2D | 3.91% | 57.93% | 7.8% | 15.9% | 9.3% | 26.7% | 42.5% | 56.2% |
| Tuesday June 2nd, 2020 | 40W, 3D | 3.81% | 61.79% | 7.6% | 23.6% | 10% | 28.2% | 44.5% | 58.5% |
| Wednesday June 3rd, 2020 | 40W, 4D | 3.68% | 65.54% | 7.4% | 31.1% | 10.7% | 29.8% | 46.6% | 60.6% |
| Thursday June 4th, 2020 | 40W, 5D | 3.52% | 69.15% | 7% | 38.3% | 11.4% | 31.3% | 48.6% | 62.7% |
| Friday June 5th, 2020 | 40W, 6D | 3.33% | 72.57% | 6.7% | 45.1% | 12.1% | 32.9% | 50.5% | 64.7% |
| Saturday June 6th, 2020 | 41W, 0D | 3.12% | 75.8% | 6.2% | 51.6% | 12.9% | 34.4% | 52.4% | 66.6% |
| Sunday June 7th, 2020 | 41W, 1D | 2.9% | 78.81% | 5.8% | 57.6% | 13.7% | 36% | 54.3% | 68.5% |
| Monday June 8th, 2020 | 41W, 2D | 2.66% | 81.59% | 5.3% | 63.2% | 14.4% | 37.5% | 56.1% | 70.2% |
| Tuesday June 9th, 2020 | 41W, 3D | 2.42% | 84.13% | 4.8% | 68.3% | 15.2% | 39% | 57.9% | 71.9% |
| Wednesday June 10th, 2020 | 41W, 4D | 2.18% | 86.43% | 4.4% | 72.9% | 16.1% | 40.5% | 59.6% | 73.5% |
| Thursday June 11th, 2020 | 41W, 5D | 1.94% | 88.49% | 3.9% | 77% | 16.9% | 42% | 61.3% | 75.1% |
| Friday June 12th, 2020 | 41W, 6D | 1.71% | 90.32% | 3.4% | 80.6% | 17.7% | 43.4% | 62.9% | 76.4% |
| Saturday June 13th, 2020 | 42W, 0D | 1.5% | 91.92% | 3% | 83.8% | 18.6% | 44.8% | 64.5% | 77.8% |
| Sunday June 14th, 2020 | 42W, 1D | 1.3% | 93.32% | 2.6% | 86.6% | 19.5% | 46.3% | 65.9% | 79.2% |
| Monday June 15th, 2020 | 42W, 2D | 1.11% | 94.52% | 2.2% | 89% | 20.3% | 47.6% | 67.3% | 80.5% |
| Tuesday June 16th, 2020 | 42W, 3D | 0.94% | 95.54% | 1.9% | 91.1% | 21.1% | 48.9% | 68.8% | 81.6% |
| Wednesday June 17th, 2020 | 42W, 4D | 0.79% | 96.41% | 1.6% | 92.8% | 22% | 50.1% | 70.2% | 82.7% |
| Thursday June 18th, 2020 | 42W, 5D | 0.66% | 97.13% | 1.3% | 94.3% | 23% | 51.6% | 71.4% | 83.6% |
| Friday June 19th, 2020 | 42W, 6D | 0.54% | 97.72% | 1.1% | 95.4% | 23.7% | 53.1% | 72.8% | 84.6% |
| Saturday June 20th, 2020 | 43W, 0D | 0.44% | 98.21% | 0.9% | 96.4% | 24.6% | 54.2% | 73.7% | 85.5% |
| Sunday June 21st, 2020 | 43W, 1D | 0.35% | 98.61% | 0.7% | 97.2% | 25.2% | 55.4% | 74.8% | 86.3% |
| Monday June 22nd, 2020 | 43W, 2D | 0.28% | 98.93% | 0.6% | 97.9% | 26.2% | 56.1% | 75.7% | 87.9% |
| Tuesday June 23rd, 2020 | 43W, 3D | 0.22% | 99.18% | 0.4% | 98.4% | 26.8% | 57.3% | 76.8% | -% |
| Wednesday June 24th, 2020 | 43W, 4D | 0.18% | 99.38% | 0.4% | 98.8% | 29% | 58.1% | 79% | -% |
| Thursday June 25th, 2020 | 43W, 5D | 0.14% | 99.53% | 0.3% | 99.1% | 29.8% | 59.6% | -% | -% |
| Friday June 26th, 2020 | 43W, 6D | 0.1% | 99.65% | 0.2% | 99.3% | 28.6% | 62.9% | -% | -% |
| Saturday June 27th, 2020 | 44W, 0D | 0.08% | 99.74% | 0.2% | 99.5% | 30.8% | -% | -% | -% |
| Sunday June 28th, 2020 | 44W, 1D | 0.06% | 99.81% | 0.1% | 99.6% | 31.6% | -% | -% | -% |
| Monday June 29th, 2020 | 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.