Farts are a natural and common bodily function that we all experience. While farts can sometimes be embarrassing, they are a healthy and expected part of digestion. Since farts involve gas being passed from your digestive system, one may wonder about the actual physical traits of farts, including their mass and weight. Here we will look at the available research to estimate the weight of the average fart.
What causes farts?
Farts are small pockets of gas that build up in the digestive system and are then passed out of the body through the anus. They often have an unpleasant odor because they contain trace amounts of hydrogen sulfide gas. This gas is produced when bacteria in the large intestine help break down food.
Most farts are produced from air that we swallow while eating and drinking. We take in a lot of air when we eat or drink quickly, chew gum, smoke, or drink carbonated beverages. This air eventually makes its way through the digestive system and comes out the other end as a fart.
In addition to swallowed air, gases produced as food is broken down in the large intestine also contribute to farting. Certain foods produce more gas as they are digested, such as beans, vegetables, grains, and dairy products.
Factors that influence fart weight
There are several factors that can influence the mass and weight of the average fart. These include:
- Gas volume – The amount of gas present will impact the overall weight.
- Gas composition – Farts contain varying amounts of different gases, including nitrogen, oxygen, carbon dioxide, hydrogen and methane. The molecular weight of each gas affects the total weight.
- Humidity and water vapor – Farts can contain a small amount of moist air, adding some weight.
- Diet – What foods you eat impacts the composition and volume of intestinal gases.
- Individual variation – Factors like health, metabolism and genetics influence fart production and composition.
Calculating fart weight
While farts are challenging to study directly, we can come up with an estimate for the weight of an average fart based on their known properties. Here are some key parameters to consider:
- Average fart volume – Estimates range from 33 to 125 mL.
- Average fart composition:
- 60-90% nitrogen
- 5-10% hydrogen
- 10-30% carbon dioxide
- 2-5% oxygen and methane
Given this composition and a typical 100 mL volume, we can calculate the contribution of each gas to the total mass of a fart as follows:
Nitrogen
- Molecular weight: 28 g/mol
- 90% of 100 mL is 90 mL
- Gas volume to moles: 90 mL / 22.4 L/mol = 0.004 mol
- Moles to mass: 0.004 mol * 28 g/mol = 0.112 g
Hydrogen
- Molecular weight: 2 g/mol
- 5% of 100 mL is 5 mL
- Gas volume to moles: 5 mL / 22.4 L/mol = 0.0002 mol
- Moles to mass: 0.0002 mol * 2 g/mol = 0.0004 g
Carbon dioxide
- Molecular weight: 44 g/mol
- 30% of 100 mL is 30 mL
- Gas volume to moles: 30 mL / 22.4 L/mol = 0.001 mol
- Moles to mass: 0.001 mol * 44 g/mol = 0.044 g
Oxygen and methane
- Combined molecular weight: ~32 g/mol
- 5% of 100 mL is 5 mL
- Gas volume to moles: 5 mL / 22.4 L/mol = 0.0002 mol
- Moles to mass: 0.0002 mol * 32 g/mol = 0.0064 g
Adding up the mass contributions from each gas:
Nitrogen: 0.112 g
Hydrogen: 0.0004 g
Carbon dioxide: 0.044 g
Oxygen and methane: 0.0064 g
Total mass = 0.1628 g
Therefore, for a typical fart volume of 100 mL, the estimated mass comes out to about 0.16 g, or roughly 1/6 of a gram.
Variation in fart weight
The weight of farts can vary considerably depending on the volume of gas passed and composition:
- Small fart: 33 mL, ~0.05 g
- Average fart: 100 mL, ~0.16 g
- Big fart: 125 mL, up to 0.2 g
Diet can significantly influence the gases present. Someone following a plant-based diet rich in fiber produces farts with more hydrogen and methane. A diet higher in animal products and lacking fiber leads to farts with more nitrogen and carbon dioxide.
How fart weight compares to other small objects
To put the mass of farts in perspective, here’s how their weight compares to some other very light objects:
| Object | Weight |
|---|---|
| Small fart (33 mL) | 0.05 g |
| Medium fart (100 mL) | 0.16 g |
| Large fart (125 mL) | 0.2 g |
| Paperclip | About 1 g |
| Nickel | 5 g |
| Ping pong ball | 2.7 g |
| Marshmallow | 2-4 g |
| US penny | 2.5 g |
As you can see, even a big fart of 125 mL weighs much less than a penny!
Fun facts about fart weight
- The gases in farts weigh very little, but can produce a strong odor.
- On Earth, farts are held down by gravity and have some mass. But in space, astronaut farts would just dissipate!
- The world’s longest fart was 2 minutes and 42 seconds, but it’s unknown how much it weighed.
- Scientists think the average person passes gas around 14 times per day, producing quite a bit of weight in fart mass.
- Dogs, cows and other methane-producing animals have much larger and heavier farts than humans.
- Farts contain microscopic fecal matter that adds a tiny amount of weight.
- A fart can weigh slightly more if it contains a small amount of liquid or mucus.
The bottom line on fart weights
The typical human fart ranges from about 33 to 125 mL in volume and contains varying amounts of different gases. Factors like diet, individual variation and humidity of the air impact the makeup of the gases. By calculating the mass contribution from each component gas, we can estimate the weight of an average fart to be about 0.05 – 0.2 grams, or up to 1/5 of a gram.
While farts may sometimes smell bad and cause embarrassment, they are a natural and healthy bodily function. The gases themselves weigh very little, even for a big fart. The modest weight of farts is just one more scientific insight into understanding more about this perfectly normal and slightly humorous bodily process!