What is Body Armor?

Body armor is a broad term that encapsulates all types of protective gear designed to prevent injury, but most well known is armor designed to stop bullets and shrapnel. Originating from the armor worn by warriors in ancient battles, modern body armor has come a long way in terms of technology and effectiveness. Today’s body armor is classified into two major categories, soft body armor which is designed to protect against handguns, and hard body armor designed to protect against rifle rounds. The great thing about body armor is that it comes in many shapes and forms for different needs and scenarios. From bulletproof vests used by law enforcement to bomb suits used by military EOD specialists, body armor has evolved to meet the challenges of modern warfare and law enforcement.

How Body Armor Works

Body armor works by dissipating the energy of an impact, in this case a projectile, over a large surface area and preventing the penetration of the projectile. This process involves a combination of different materials and design strategies, depending on the type of body armor. When a bullet strikes body armor, a sequence of physical events occurs. 

The force of impact depends on the mass of the bullet, its velocity, and the distance over which it is stopped. According to Newton’s second law of motion (F=ma) the force exerted on the armor is equal to the rate of change of momentum of the bullet. The faster and heavier the bullet, the more force it exerts on the armor.

The bullet carries kinetic energy, which according to the basic physics principle, must be transferred upon impact. The body armor’s job is to absorb and redistribute this energy to prevent the bullet from penetrating.

Soft Body Armor

Soft body armor, commonly referred to as bulletproof vests, is often made from high strength fiber materials like Kevlar. When a bullet strikes the vest, the energy is absorbed by these fibers and spread over a larger area.

The individual layers of fiber in the vest are designed to move, flex, and stretch. This means that when a bullet hits the vest, the layers will deform, absorbing and distributing the energy throughout the vest and slowing the bullet down. As the bullet penetrates deeper more and more layers will deform to absorb the energy until the bullet is stopped. While the wearer will still feel the impact and sustain bruising or minor injuries, the vest prevents the bullet from penetrating the body.

Bulletproof vest
Soft body armor

Types of Soft Body Armor

There are primarily two types of soft body armor, covert and overt.

Covert body armor is concealed body armor, this type is worn under clothing and is designed to be unnoticeable. It is commonly used by law enforcement, security, and private citizens for personal protection.

Concealed body armor
Covert body armor

Overt body armor is worn over clothing and is visible. It’s typically used by police in certain situations like riots, warrant service, etc. Overt body armor often includes additional features like pouches for equipment, MOLLE attachments, extra magazines, etc.

Tactical vest
Overt tactical vest

Materials Used in Soft Body Armor

The most commonly known material used in soft body armor is Kevlar, a high strength para-aramid fiber developed by DuPont. Kevlar is five times stronger than steel on an equal weight basis, and it can absorb and disperse energy effectively, making it ideal for body armor.

I would like to note because we will be covering steel body armor later, and just because something is stronger than steel does not mean it will stop the same rounds. Kevlar relies on fibers that are movable as stated above, whereas steel relies on its rigidity.

Therefore, even though Kevlar is stronger than steel it lacks the rigidity, which makes it great for soft armor but limits Kevlar’s effectiveness against rifle rounds.

Kevlar armor
UHMWPE soft armor

Other materials used in soft body armor include Twaron (a Kevlar variant), Spectra, Dyneema, and forms of UHMWPE (Ultra high molecular weight polyethylene). These are all high strength synthetic fibers that offer excellent ballistic protection and are about 3 times stronger than Kevlar.

Levels of Soft Body Armor

The National Institute of Justice (NIJ) rates body armor based on its ability to stop specific ammunition. Soft body armor falls into Levels IIA, II, and IIIA.

Level IIA is designed to stop 9mm and .40 S&W ammunition. This is the lightest and thinnest type of soft body armor and offers the least amount of protection.

Level II is designed to stop 9mm and .357 Magnum ammunition. This offers a higher level of protection than IIA.

Level IIIA is the highest level of protection offered by soft body armor and is designed to stop .357 SIG and .44 Magnum ammunition.

Pros and Cons of Soft Body Armor

With everything in life, there are benefits and drawbacks. It’s important to note that the right body armor depends on the specific threats a person is likely to encounter. Soft body armor offers a good balance of protection, comfort, and concealability for many situations, but it may not be the best choice for every scenario. 

Let’s discuss the pros and cons of soft body armor. 


  • Comfort: Soft body armor is flexible and conforms to the body making it more comfortable to wear for extended durations.
  • Concealability: Especially with covert armor, it can be worn without attracting attention.
  • Lightweight: Made from light, high strength fibers, soft body armor doesn’t significantly add to the wearer’s load.
  • Good coverage: Because it is flexible, this armor can conform and wrap around the body covering more surface area than hard armor. 


  • Limited Protection: Soft body armor is not designed to stop rifle rounds. For those threats, hard body armor is necessary.
  • Vulnerability to Edged Weapons: While effective against bullets, some soft body armor can be penetrated by knives or other sharp objects. Special stab resistant vests are available for situations where this is a concern.
  • Heat and Sweat: Like any heavy clothing, wearing body armor can be hot and cause the wearer to sweat which is uncomfortable. 

Hard Body Armor

Hard body armor conversely, is designed to protect against rifle rounds such as 7.62×51 and comes in different forms. This type of armor includes a hard plate made from materials such as ceramics, polyethylene, or steel. The plates are inserted into a carrier, which holds them in place over vital areas of the body.

Rifle armor
Hard body armor

When a bullet strikes a hard armor plate, the plate absorbs the impact and disperses the energy over a large surface area. The front face of the plate is designed to shatter and deform, which helps to absorb the bullet’s energy and slow it down. Then, the layers behind this face capture the bullet fragments and prevent them from penetrating further.

With steel armor the process is a little different, steel relies on its strength in relation to the bullet to be an ‘impenetrable barrier’ that the bullet smashes up against and shatters.

The best type of body armor depends on the potential threats faced by the wearer. For example, law enforcement officers may wear soft body armor while on patrol but switch to hard body armor during high risk warrant operations. Military, due to the higher risk of encountering rifle fire, wear hard body armor.

Hard armor plates primarily come in two types.

  • Stand Alone plates are designed to offer rated protection without the need for soft armor backing. They’re thicker and heavier but offer more protection as the plate backer is already part of the plate.
  • In-Conjunction-With plates are designed to be worn with soft armor backing. The soft armor helps to achieve the plate’s rated level of protection. They are generally thinner and lighter than stand alone plates but require additional soft armor to function effectively.

All ceramic rifle plates utilize some sort of backer, stand alone ceramic plates already have the backer as a part of the plate.

Materials Used in Hard Armor Plates

Various materials are used in the construction of hard armor plates, each offering different levels of protection, weight, and cost.

Types of body armor
Types of hard body armor

Steel plates are the most traditional form of hard armor. They’re durable, resistant to multiple hits, and the most affordable option. However, they’re also the heaviest type of armor plate and can produce dangerous bullet fragmentation. Therefore, special coatings or sleeves must be applied to protect the wearer from secondary injury.

Ceramic plates are lighter than steel and are designed to break up the bullet upon impact as they break apart the bullet. They offer protection against larger calibers and armor piercing rounds (In the Level 4 configuration) but are vulnerable to repeated hits in the same area. These plates incorporate a hard ceramic strike face that breaks upon impact, and a soft, generally UHMWPE backer, to give the plate strength and disperse energy.

Body armor
Ceramic body armor

Polyethylene plates are made from ultra-high molecular weight polyethylene (UHMWPE), a very tough material. Polyethylene plates are the lightest available and are capable of stopping certain rifle rounds, but they’re also the most expensive, and have limitations against ammunition that utilizes any sort of steel because they lack a hard strike face.

Levels of Hard Armor Plates

Hard armor plates are categorized into Level III and Level IV by the NIJ.

Level III is the entry level rifle plates and are designed to stop six spaced hits of 7.62x51mm NATO rounds, with less than 44mm of back face deformation on the first two shots. 

Level IV plates are exclusively ceramic plates and is the highest level of body armor currently available and can stop one hit from a .30-06 armor piercing round, and lower threats.

Pros and Cons of Hard Armor Plates


Protection: Hard armor plates offer a higher level of protection compared to soft body armor. They’re designed to stop rifle rounds, which soft armor cannot.

  • Durability: Especially with steel plates, hard armor can often withstand multiple hits.
  • Variety: With different materials and types to choose from, users can select the plates that best meet their needs in terms of protection, weight, and cost.
  • Threat level: Hard armor plates are capable of stopping rifle rounds.


  • Weight: Hard armor plates are heavier than soft armor, which can be a hindrance to users who need to move quickly or wear the armor for hours on end.
  • Comfort: The rigid plates don’t conform to the body, making them less comfortable to wear than soft armor. 
  • Limited protection: Hard armor plates cover less of the body due to weight and rigidity, leaving more exposed.
  • Cost: Particularly for ceramic and polyethylene plates, hard armor can be quite expensive.

As with soft body armor, the best choice of hard armor plates depends on the specific threats a person is likely to encounter. Hard armor offers more protection but comes with tradeoffs in terms of weight, coverage, comfort, and cost.

Modern Developments in Body Armor

Today’s body armor technology is not only about stopping bullets. Modern body armor designs also consider factors such as comfort, weight, and mobility, which are important for the wearer’s performance. Innovations include the use of lightweight, high strength materials and designs that distribute weight more evenly to reduce fatigue.

Carriers and Vests

Body armor carriers, referred to as vests or plate carriers are the component of the body armor system that holds the protective plates or panels. They are essentially the shell into which the soft armor or hard plates are inserted. Vests come in a variety of styles to accommodate different types of armor and specific needs.

  • Soft Armor Carriers: These are designed to hold soft armor panels that provide Level IIA, II, or IIIA protection. They often have pockets for additional hard armor plates if they are overt vests. If they are covert vests they will be slick, thin, and soft.
  • Plate Carriers: These are designed to hold hard armor plates. Plate carriers tend to be more modular, with MOLLE (Modular Lightweight Load-carrying Equipment) webbing for attaching additional gear and accessories.
Plate carrier
Plate carrier
  • Hybrid Carriers: These are versatile carriers designed to hold both soft armor and hard armor plates, allowing the wearer to adjust their level of protection as needed. This is typical of military issued armor, where soldiers use hard plates to cover vital areas, and soft armor everywhere else to protect from shrapnel.

Vests and carriers can also be either covert, designed to be worn under clothing and conceal the armor, or overtly worn over clothing and openly displaying the armor and allowing the user to attach accessories

NIJ Testing

NIJ armor ratings
NIJ threat ratings

The National Institute of Justice (NIJ) is responsible for setting and enforcing standards for body armor. The NIJ conducts rigorous testing to ensure that body armor meets established safety standards.

For body armor, the NIJ tests both soft and hard armor against various types and calibers of ammunition. The armor is shot with the specified rounds in a controlled environment, and the amount of force transmitted through the armor is measured. To pass the test, the armor must prevent the bullet from penetrating, and the amount of deformation on the back side must be below a specific threshold for that threat rating.

The NIJ tests body armor for durability and performance over time. This includes subjecting the armor to conditions such as heat, moisture, and mechanical wear, then retesting it to ensure it still provides adequate protection.

The Legality of Body Armor

In the United States, federal law allows private citizens to purchase and own body armor with a few exceptions. Convicted felons are prohibited by federal law from possessing body armor.

However, certain states have additional laws regarding the purchase, possession, and use of body armor. For example, Connecticut requires sales of armor to be in-person transactions. 

Other states prohibit wearing body armor during the commission of a crime.

Before purchasing body armor, understand the laws in your specific location to ensure you are in compliance.

In other countries, the legality of body armor varies widely, with some allowing unrestricted ownership and others requiring a permit or outright banning civilian possession. Always check local laws and regulations before purchasing or using body armor.

How To Wear Body Armor Properly

Correctly wearing body armor is important to make sure it will actually protect you the way it is supposed to. Here are a few tips to ensure you get a great fit with your body armor.

  • The armor should fit snugly against your body. If the armor is too loose it will slide around during movement, unbalancing the user and shifting coverage. If the armor is too tight it can restrict breathing, especially when moving quickly or under stress. 
  • The top edge of the front panel should sit approximately 1/2-1 inch below your sternal notch (the hollow at the base of your throat). The back panel should be at the same height as the front when standing. 
  • The armor should cover your vital organs, mainly heart, lungs, and upper abdomen.
  • The armor is secured with shoulder and waist straps. These should be fastened so that the armor is held firmly in place but not so tight as to be uncomfortable or restrict movement.
  • It’s always a good idea to fit your armor in front of a mirror to ensure it is in place for proper coverage. Remember that body armor is designed to protect you, and a poor fit will compromise protection.

Body Armor Maintenance and Care

Proper maintenance and care will help extend the lifespan of your body armor and continue to provide effective protection.

  • Cleaning: Body armor carriers can be washed, but always check the manufacturer’s instructions. Washing machines are generally not advised, however certain concealable soft armor carriers can be. Armor panels and plates should not be washed. Instead, remove the panels or plates and wipe them down with a damp cloth. Never use bleach or other harsh chemicals.
  • Storage: Store body armor flat at room temperature. Avoid folding or bending the armor, as this can damage it. Keep it out of direct sunlight and avoid high humidity or extreme temperature conditions.
  • Inspection: Regularly inspect your body armor for signs of wear and tear. Look for cuts, tears, or fraying in the fabric. Check hard armor plates for cracks or other damage. If you find any signs of damage, replace the armor immediately.
  • Lifespan: Even with proper care, body armor doesn’t last forever. The NIJ recommends replacing soft armor every five years, but check the manufacturer’s guidelines as the lifespan can vary. Hard armor plates generally have a warranty period of 5 to 10 years, but they should still be replaced if you notice any signs of damage.

Remember, body armor is a critical piece of safety equipment, and it should be treated as such. Regular maintenance and care will help ensure it can do its job effectively.

Common Body Armor Questions

Body armor is a piece of equipment that saves lives, but it’s also a technology that can raise questions. Here are some commonly asked questions about body armor.

What factors determine a bullet’s ability to penetrate armor?

Several factors can affect a bullet’s ability to penetrate armor. These include the bullet’s size, speed, material, shape, and design. Armor piercing bullets are specifically designed to penetrate armor, and will incorporate a large steel or tungsten core. The quality and level of the armor are also critical factors in its ability to stop a bullet.

What is backface deformation?

Backface deformation refers to the dent or bulge that forms on the backside of body armor when a bullet strikes it. Even if the bullet doesn’t penetrate the armor, the force of the impact can cause the armor to deform.

How do you prevent backface deformation injuries?

Trauma pads are worn behind body armor, they are designed to help prevent backface deformation injuries. These pads absorb and distribute the force of the bullet’s impact by providing an additional layer of non-ballistic protection.

Why can’t a bulletproof vest stop a knife?

While some vests are designed to stop knives, not all are. Bullets and knives pose different threats. Bullets deliver a high speed impact with a small surface area, while knives deliver a slower, forceful impact with a more pointed surface area. Therefore, different materials and designs are required to stop these different threats effectively.

Can a bulletproof vest stop a 50 cal?

Standard bulletproof vests and even hard body armor plates cannot stop a .50 caliber bullet. The sheer energy and velocity of a .50 caliber round makes it extremely difficult to stop. Currently, there are no known body armor plates rated to stop a .50 cal bullet.

Can body armor break?

Yes, particularly hard armor plates made of ceramic can break or crack if subjected to high stresses or impacts. Regular inspection of armor is important to ensure its integrity.

Who invented body armor?

While forms of body armor have been used throughout history, the modern bullet resistant vest was invented by Richard Davis, a former U.S. Marine. He founded Second Chance Body Armor in the early 1970s and developed the first commercial bulletproof vest using Kevlar.

Can you survive a shotgun blast with a bulletproof vest?

The survival rate depends on the type of body armor worn and the ammunition used. Hard body armor can stop shotgun blasts as can level IIIA depending on the load. However, the force of the blast could still cause injuries, even if the pellets are stopped. Further, the spread of the blast poses risks to be hit outside the covered areas.

Is body armor actually bulletproof?

The term “bulletproof” is somewhat misleading. No body armor can guarantee complete protection against all bullets. Instead, body armor is rated to resist specific types and calibers of bullets, so bulletproof vs bullet resistant is more accurate. 

What’s the strongest body armor?

The strongest body armor is Level IV hard armor, which is designed to stop armor piercing rifle rounds.

Final Thoughts

Body armor is an essential piece of protective equipment, in any walk of life. Understanding how it works, its different types and materials, how to properly wear and care for it, and its legal implications is important for anyone who might need to use it.

While body armor can provide protection against various threats, it’s important to remember that no armor is entirely “bulletproof.” The armor’s effectiveness depends on its level, the type and velocity of the bullet, and the specific circumstances of the threat.

Furthermore, using body armor doesn’t eliminate the need for other safety measures, such as situational awareness and the appropriate use of cover and concealment. Body armor works by using advanced materials, hard or soft, to disperse the energy of a bullet and create a barrier between the wearer and the round. 

It’s also important to remember that body armor has limitations and tradeoffs. Hard armor offers more protection than soft armor but is also heavier and less comfortable. Some armor can stop bullets but not necessarily knife attacks. And while body armor can save lives, it’s not a guarantee of safety.

Regardless of these limitations, body armor continues to be an exceptional tool in saving lives and reducing injuries from gunfire. As technology advances, we can expect to see even better body armor in the future.

The opinions expressed in this post are those of the author and do not necessarily reflect the views and opinions of Tacticon Armament.