Bullets can cause devastating injuries when they enter the human body. However, there has been some speculation that a very fat person may be able to stop a bullet due to their thick layer of body fat. So how much fat is actually needed to stop a bullet?
The penetrative ability of bullets
To understand if fat can stop a bullet, we first need to examine how much penetrating power bullets have. The penetration ability of a bullet depends on multiple factors:
- Bullet caliber – The diameter of the bullet. Larger caliber bullets have more mass and momentum and can penetrate deeper.
- Bullet velocity – The speed at which the bullet travels. Faster bullets impart more kinetic energy and penetrate further.
- Bullet design – Features like a full metal jacket or hollow point affect penetration.
- Bullet material – Lead, steel, or other metals have differing densities and strengths.
- Target material – Dense bone or muscle requires more force than fat or organs.
- Angle of impact – Perpendicular shots penetrate deeper than angled shots.
In ballistics testing, bullets are typically fired into blocks of a material called ballistic gelatin. These gelatin blocks are designed to simulate human tissue.
Handgun bullets such as 9mm or .45 caliber can penetrate 12-18 inches of ballistic gelatin before stopping. High velocity rifle bullets of calibers like 5.56mm or 7.62mm can penetrate over 30 inches of gelatin.
These tests give us a reference point for how much tissue a bullet can potentially pass through. Clearly several feet of fat would be required to have a chance at stopping a bullet.
Body fat layers in obese people
Next we need to consider typical body fat depths in very overweight or obese individuals. Where on the body are the thickest fat layers located?
In one study, CT scans were used to measure the fat depth at various body sites in a group of obese individuals (BMI > 30). The results were:
| Body site | Fat depth (cm) |
|---|---|
| Abdomen | 3.9 |
| Buttocks | 3.2 |
| Thigh | 2.4 |
| Chest | 2.8 |
Based on this data, the thickest fat layers were found around the abdomen and buttocks, with depths of around 4 cm (1.5 inches). Other studies have found similar results, with maximum fat depths typically less than 5 cm (2 inches) even in morbidly obese individuals with BMIs over 40.
Likelihood of a bullet being stopped
Now that we have ballpark numbers for both bullet penetration and body fat depth, we can estimate the chance of a bullet being stopped by body fat alone.
For typical handgun bullets, 12-18 inches of penetration would be expected in tissue. With abdominal fat depths unlikely to exceed 2 inches, it is highly improbable that enough fat is present to stop a bullet before it reaches organs or bone.
Higher velocity rifle bullets have even greater potential for penetration. So for these, there is essentially no chance of body fat providing adequate protection.
There are a few potential caveats. Bullet caliber, velocity, trajectory, and fat distribution all affect the precise interaction. A distant shot with a low velocity round that only travels 6-8 inches and hits at an oblique angle could theoretically be impeded by fat alone before reaching vital organs. But such an occurrence would be rare and unreliable.
Real-world examples
There are few documented cases of body fat actually stopping a bullet in real gunshot incidents:
- In one instance, a very obese bank robber was shot by police six times with 9mm bullets and survived. However, the fat likely only slowed the bullets rather than stopped them completely before they reached organs.
- A heavyset man in Las Vegas survived a .22LR shot to the stomach because of his girth. Again though, the bullet was likely slowed and deflected rather than fully stopped.
- Some claims exist of bullets getting lodged in large folds of fat in obese victims. But it is unclear if penetration to inner tissue still occurred.
So while body fat may sometimes slow or deflect lower velocity bullets, complete penetration to inner tissue and organs most often still occurs.
Effect of clothes and body armor
Thus far we have only considered protection from body fat alone. In reality, clothes and purpose-designed body armor are far more effective than fat at stopping bullets.
Materials like Kevlar fibers absorb a bullet’s energy and spread out its force to prevent penetration. Clothes may act as an extra layer on top of fat to impede bullets.
With body armor, the wearer’s body composition and amount of fat does not make a significant difference. Proper fit is more important than girth. So an obese person does not gain any real advantage over a thinner person by wearing the same bulletproof vest.
The importance of shot placement
While body fat provides minimalbullet protection, shot placement on the body is actually more crucial to survival. Bullets that avoid the heart, lungs, major blood vessels, and central nervous system are less likely to cause rapid death or incapacitation.
A shot straight into the chest or head is far more dangerous than one to an extremity. Hitting only fat and muscle in an arm or leg is unlikely to take someone out of the fight immediately or cause rapid blood loss.
So in most defensive shooting situations, accurately aimed shots at center mass vital zones give the best chance of stopping an attacker swiftly, regardless of their body size.
Conclusion
In summary, it is unlikely that fat alone provides adequate protection against bullets. Typical fat layer depths are far less than the 12+ inches of penetration that many bullets can achieve. While cases exist of bullets being slowed or deflected by fat, complete penetration to inner organs and tissues still usually occurs.
Purpose-designed body armor is more reliable than fat for stopping bullets. And shot placement is actually more important than girth for survival and incapacitation when being shot. So while extra body fat may potentially slow some bullets slightly, it cannot be counted on to stop them completely in most cases.