Australia's national science agency spent three months asking people to tap a button on their phone every time they passed gas. The app was called Chart Your Fart. More than 19,000 people consented to take part, 6,416 produced usable data, and together they logged 360,192 individual events.
The headline number is the one nobody expected. The median participant passed gas 3.8 times a day. That sits below the range printed in nutrition textbooks and well under what U.S. federal health information tells the public is typical.
The findings were published in late May in JAMA Network Open by Emily Brindal and Danielle Baird of the CSIRO Health and Biosecurity unit in Adelaide.
Where the Familiar Numbers Come From
The figures in circulation have never been measured this way. Nutrition textbooks put the normal range at 5 to 20 outputs per day, scaled to fiber intake. The National Institute of Diabetes and Digestive and Kidney Diseases tells Americans that studies suggest an average of 8 to 14 times a day, with up to 25 considered normal.
Those estimates rest largely on small laboratory studies and retrospective surveys, some decades old. A 1991 study of healthy volunteers that collected gas directly over 24 hours recorded a median of eight emissions. A diary study of 25 people found a mean of 10 a day over a week. A survey of about 16,000 Americans who reported gas or bloating produced age patterns the Australian data broadly matched, though it relied on people recalling their own frequency rather than logging it.
The Australian researchers make the point sharply in their introduction, noting that most investigators "have shied away from asking how frequently the average person passes gas."
What the Real-Time Data Showed
Participants were recruited through a national media campaign, consented digitally in the app, and were asked to log each event as close as possible to the moment it happened, across at least two weekdays and one weekend day. Data were collected from November 2024 through February 2025.
The sample mean was 5.0 per day. The median was 3.8, with a middle range of 2.5 to 6.2. Nearly four in five participants, 5,085 people, fell between 2 and 7 a day.
Men recorded a little more than women, roughly 5.2 against 4.8, a gap of less than half an emission a day that the researchers say may partly reflect self-reporting rather than physiology. The youngest group, ages 14 to 25, recorded fewer than every other age group.
There was also a clear rhythm across the day. Activity climbed gradually and peaked between 6 and 10 p.m., with a noticeable dip in the middle of the day. That pattern tracked national data on when Australians consume most of their energy and fiber.
The Gap Between Feeling Excessive and Being Excessive
The reason any of this matters is a mismatch CSIRO had already documented. When the agency launched the campaign in November 2024, it cited its own 2021 gut health study in which more than 60 percent of Australians reported what they considered excessive flatulence, with up to 43 percent saying they experienced it most days.
Set that against a median of under four events a day and a large majority sitting between 2 and 7, and the picture that emerges is a population worried about a number most of them have never actually counted. Without a reference point, "excessive" is a feeling.
The researchers frame their data as exactly that reference point, describing it as a starting point for conversations about excess rather than a diagnostic threshold. They also read the response itself as a finding. High participation and sustained engagement, they argue, suggest flatulence is a subject people want addressed rather than joked past, and one that deserves more clinical discussion than it gets.
What the Study Cannot Tell You
This is a cross-sectional study of self-reported behavior, not a physiological measurement, and it establishes patterns rather than causes. Several limitations matter.
Nothing passed during sleep was captured. Participants could not log a day with no flatus at all, so days without entries were indistinguishable from days with no gas, which may have pushed the observed averages upward. Entries could also be time-stamped retrospectively rather than only in the moment.
Recruitment was not random. People who volunteer for a flatulence tracking app may be more interested in gut health or more comfortable with technology than the general population. The findings describe Australians, not Americans, and diets differ.
Frequency is also partly a social variable rather than a biological one. People choose when to release gas, and cultural norms shape that choice, which means the count reflects behavior as much as digestion. Frequency also says nothing about volume, so two people with identical counts may be producing very different amounts of gas.
None of this changes when to get checked. Federal guidance is that gas symptoms warrant a conversation with a doctor if they bother you, if they change suddenly, or if they arrive alongside abdominal pain, constipation, diarrhea or weight loss.
Key Questions Answered
How many times a day did participants actually pass gas?
The median was 3.8 times per day, and the mean was 5.0. About 79 percent of the 6,416 participants recorded between 2 and 7 a day.
Why is that different from what I have read elsewhere?
Commonly cited figures of 8 to 14 or 5 to 20 per day come mostly from small laboratory studies and surveys. This study captured flatulence in real time in a large general population sample instead.
Does this mean I have a problem if I pass gas more often?
No. The study describes what was typical in one Australian sample, not a threshold for disease. Diet, medication, and health conditions all shift the number.
When was the data collected?
Participants logged entries between November 2024 and February 2025. The study was published in JAMA Network Open in late May.
What were the main limitations?
Self-reported data, no capture of gas passed during sleep, no way to log a day with zero events, non-random recruitment, and no measurement of volume.
When should someone see a doctor about gas?
Federal health guidance says to talk with a doctor if gas symptoms bother you, change suddenly, or occur with abdominal pain, constipation, diarrhea or weight loss.
