Muzzle Energy for Air Guns

Muzzle Energy for Air Guns


Use this free Muzzle Energy calculator to find out the FPE or FPS of your Airguns.

Select (FPE) to find out the foot-pounds of energy of the exiting pellet.

Select (FPS) to find out the feet per second velocity of the exiting pellet.


This Muzzle Energy for Air Guns tool was built by Just Air Guns to help airgun enthusiasts calculate the FPS and FPE of their airguns. Below, we explain both FPS and FPE in detail. However, it is important that you understand that Muzzle Energy for Air Guns must stay within the legal limits set by law.


The FPS (feet per second) of an airgun refers to the velocity at which the projectile (usually a pellet or a BB) travels when fired from the gun. FPS is a crucial specification as it directly impacts the airgun’s performance in terms of accuracy, range, and power. The FPS of an airgun can vary widely depending on factors such as:

Type of Airgun: Different types of airguns, such as spring-piston, CO2-powered, or pre-charged pneumatic (PCP), can have varying FPS capabilities.

Calibre: The calibre of the airgun (e.g., .177, .22) also influences its FPS. Generally, higher calibres tend to have lower FPS compared to lower calibres due to factors like the weight and size of the projectile.

Power Source: The mechanism powering the airgun, such as a spring, CO2 cartridge, or compressed air tank, affects its FPS capabilities. For example, PCP airguns often have higher FPS than spring-piston airguns due to their higher power output.

Barrel Length: The length and design of the barrel can impact the velocity of the projectile as it travels through the barrel.

Pellet Weight: The weight of the pellet being used can also affect FPS. Lighter pellets generally achieve higher velocities compared to heavier pellets when fired from the same airgun.

Typically, airgun manufacturers specify the FPS range for their products based on standard conditions (such as using specific pellets and power settings). It’s essential for airgun users to consider the FPS of their airgun when selecting ammunition, understanding the intended use (e.g., target shooting, pest control, hunting), and ensuring compliance with local laws and regulations regarding airgun power limits.


FPE stands for Foot-Pounds of Energy, and it’s a measurement of the kinetic energy transferred by a projectile when fired from an airgun. It’s an important metric for assessing the power and potential impact of an airgun, especially for hunting or pest control purposes.

The formula to calculate FPE is where:

  • Projectile Weight is measured in grains.
  • Velocity is measured in feet per second.

This formula helps determine the energy delivered by the projectile in foot-pounds. The higher the FPE, the greater the potential impact of the projectile.

Factors influencing FPE include:

  • Projectile Weight: Heavier projectiles carry more energy than lighter ones when fired at the same velocity.
  • Velocity: Higher velocities result in greater kinetic energy transfer.

When selecting an airgun, it’s crucial to consider both FPS and FPE to ensure it meets your needs, whether for target shooting, pest control, or hunting. However, it’s essential to be aware of legal regulations regarding the maximum allowable FPE for airguns in your area, as exceeding these limits may be unlawful and potentially dangerous.


If you have any questions about Muzzle Energy for Air Guns and the information on this page, please get in touch with us via the Contact Us info on this website or head over to our blog for the best in airgun news and information.