Muzzle Velocity Calculator

Calculate muzzle velocity from kinetic energy and bullet weight, or find any variable when two are known. Enter your bullet weight (grains) and kinetic energy (ft-lbf) — or swap in velocity (fps) — and get the missing value instantly. Useful for handloaders, hunters, and ballistics enthusiasts verifying firearm performance.

Choose which value you want to calculate.

gr

Bullet weight in grains (1 gr = 0.0648 g).

fps

Speed of bullet at the muzzle in feet per second.

ft-lbf

Muzzle energy in foot-pounds force.

Results

Calculated Result

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Muzzle Velocity

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Kinetic Energy

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Bullet Weight

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Bullet Weight (grams)

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Kinetic Energy (Joules)

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Muzzle Velocity (m/s)

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Energy Breakdown by Component

Results Table

Frequently Asked Questions

What is muzzle velocity?

Muzzle velocity is the speed of a bullet as it exits the barrel of a firearm, measured at the muzzle (the open end of the barrel). It is typically expressed in feet per second (fps) or meters per second (m/s). Higher muzzle velocity generally means a flatter trajectory, more energy on target, and longer effective range.

How do I calculate muzzle velocity from kinetic energy and bullet weight?

The formula is: v = √(2 × KE / m), where KE is kinetic energy in foot-pounds and m is the bullet mass in slugs (grains ÷ 225,218). Equivalently, fps = √(KE × 450,437 / weight_in_grains). This calculator does all the unit conversions for you automatically.

How fast does a bullet travel?

Bullet speed varies widely by cartridge type. Handgun rounds typically range from about 800–1,600 fps (245–490 m/s), while rifle rounds commonly travel between 2,500–4,000 fps (760–1,220 m/s). Special high-velocity rifle loads can exceed 4,500 fps. Tank cannons and artillery can push projectiles even faster.

How do I calculate the muzzle velocity of a 5.56 NATO round?

A standard 5.56×45mm NATO load with a 55-grain bullet from a 20" barrel produces approximately 3,240 fps (987 m/s) and around 1,282 ft-lbf of energy. Shorter barrels reduce velocity by roughly 25–50 fps per inch lost. Enter 55 gr and 1,282 ft-lbf in this calculator to verify.

What is the muzzle velocity of a .45 ACP with a 230-grain bullet?

Standard .45 ACP 230-grain ball ammunition typically exits the muzzle at approximately 830–850 fps (253–259 m/s), producing around 356–370 ft-lbf of muzzle energy. It is a subsonic round by design, which is why it works well with suppressors.

What is the 9mm muzzle velocity?

A standard 9mm Luger (9×19mm) load with a 115-grain bullet travels at approximately 1,180–1,200 fps (360–366 m/s), generating around 355–370 ft-lbf of energy. +P loads increase this to around 1,300 fps and 430 ft-lbf with the same bullet weight.

What is the .223 muzzle velocity of a 55-grain bullet?

A .223 Remington cartridge loaded with a 55-grain bullet from a standard 24" test barrel produces approximately 3,240 fps (987 m/s). From a typical 16" AR-15 barrel, expect around 2,900–3,000 fps. The .223 Rem and 5.56 NATO share the same bullet diameter but differ slightly in chamber dimensions and pressure.

Does barrel length affect muzzle velocity?

Yes, significantly. Longer barrels allow propellant gases more time to accelerate the bullet before it exits, increasing velocity. As a general rule, rifle cartridges gain or lose roughly 25–50 fps per inch of barrel length change. Pistol cartridges are less sensitive but still show measurable differences.

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