How Many Farts Per Day Is Normal?
The average human passes intestinal gas between 14 and 23 times per day. If that number sounds suspiciously high, that's because most of this happens quietly, unnoticed, and occasionally during meetings. Frequency is influenced by diet, gut microbiome composition, digestive speed, and individual anatomy — meaning the range of 'normal' is wider than most people assume.
The Numbers: What Research Says
The most widely cited clinical figure is 14 flatus events per day as an average, derived from studies by gastroenterologist Michael Levitt in the 1970s and confirmed by subsequent research. A 2021 review in the American Journal of Gastroenterology places the normal range at 14 to 23 per day for healthy adults. The total daily volume of intestinal gas ranges from 476 to 1,491 mL depending on diet and gut bacteria. These figures include gas passed during sleep, which accounts for a meaningful portion of the daily total and goes almost entirely unnoticed — by the person passing it, at least.
Factors That Raise or Lower Frequency
Diet is the single biggest driver of flatulence frequency. Fermentable carbohydrates — known as FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) — dramatically increase gas production when broken down by colonic bacteria. Beans, lentils, onions, garlic, wheat, and dairy products (in lactose-intolerant individuals) are primary culprits. Physical activity increases intestinal motility and tends to move gas through faster. Stress and anxiety can alter gut motility in both directions. Age is also relevant: gut microbiome composition shifts with age, often increasing fermentative activity. Eating speed matters too — faster eating swallows more air (aerophagia).
Individual Variation: A Wide Normal
Clinical studies consistently show that some healthy adults pass gas fewer than 10 times daily while others exceed 25 times without any underlying pathology. The composition of an individual's gut microbiome — which varies enormously between people — determines how efficiently different food components are fermented. Identical diets in two individuals can produce radically different amounts of gas. This means self-comparison to others is largely meaningless as a diagnostic tool. What matters clinically is a change from your own personal baseline, particularly when accompanied by pain, bloating, changes in stool, or unintentional weight loss.
When to See a Doctor
Increased flatulence alone is rarely a sign of serious illness. However, certain accompanying symptoms warrant medical evaluation. These include persistent abdominal pain or cramping, sudden changes in bowel habits, blood in the stool, unexplained weight loss, or flatulence that develops suddenly after a dietary change and does not resolve. Conditions such as celiac disease, lactose intolerance, small intestinal bacterial overgrowth (SIBO), irritable bowel syndrome (IBS), and inflammatory bowel disease (IBD) can all present with increased gas production. A food and symptom diary is often the first diagnostic step a gastroenterologist will recommend.
Did You Know?
- The clinical term for passing gas is 'flatus' — the act itself is 'flatulation' or 'flatulence'.
- Up to 99% of intestinal gas is odorless — it's the tiny fraction of sulfur compounds that causes the smell.
- Eating too quickly (aerophagia) is a significant contributor to flatulence via swallowed air.
- Astronauts in sealed spacecrafts have strict dietary guidelines partly to manage flatulence and methane buildup.
Fun Fact
A 1991 study published in Gut had volunteers eat a controlled diet and then measured their flatus output via a rectal tube over 24 hours. The most productive participant produced 53 flatus events in a single day — all while maintaining a normal diet (Tomlin et al., 1991).
Sources
- Levitt, M.D. (1971). Production and excretion of hydrogen gas in man. New England Journal of Medicine, 281(3), 122–127.
- Tomlin, J. et al. (1991). Investigation of normal flatus production in healthy volunteers. Gut, 32(6), 665–669.
- Staudacher, H.M. & Whelan, K. (2017). The low FODMAP diet: recent advances in understanding its mechanisms and efficacy in IBS. Gut, 66(8), 1517–1527.
- Suarez, F.L. et al. (1997). Bismuth subsalicylate markedly decreases hydrogen sulfide release in the human colon. Gastroenterology, 114(5), 923–929.