How Many Decibels Is a Gunshot? Levels by Caliber

Most gunshots produce peak sound pressure levels between about 140 and 175 decibels, with the majority of common recreational firearms falling in the 150 to 165 dB range.¹ That is far above the 140 dB threshold that NIOSH considers the maximum safe impulse exposure for an unprotected ear. The exact number depends on the firearm type, caliber, barrel length, ammunition, and where you are standing relative to the muzzle, and the differences across those variables are bigger than most people expect.

What Makes a Gunshot Sound So Loud

A gunshot is not a single sound. It produces at least two distinct acoustic events. The first is the muzzle blast, which is the rapid expansion of high-pressure gas escaping the barrel after the bullet leaves. This is the “bang” that dominates what the shooter hears. The second is the ballistic shockwave, sometimes called the “crack,” which is the sonic boom created by a bullet traveling faster than the speed of sound. The characteristics of both events vary with the firearm’s make, model, barrel length, and the specific ammunition loaded.²

The muzzle blast is what poses the greatest hearing risk to the shooter, because it radiates outward from the barrel end and reaches the ears at extremely high pressure in under a millisecond. The shockwave, on the other hand, propagates along the bullet’s flight path and is more relevant to bystanders or people downrange. When ammunition is subsonic, meaning the bullet travels slower than the speed of sound, the shockwave component largely disappears. Switching from supersonic to subsonic ammunition produces a noticeably greater sound reduction than the velocity change alone would suggest, because it eliminates the N-shaped pressure wave that a supersonic bullet drags along behind it.³

Decibel Levels by Caliber and Firearm Type

Specific decibel figures for individual calibers vary across studies depending on the measurement setup, microphone placement, and environment. Still, broad patterns are well-established. Peak sound pressure levels for common firearms measured at indoor and outdoor ranges have been documented between 156 and 170 dB SPL, all well above the 140 dB guideline.⁴ The following general tiers give a sense of where different firearms fall:

Small-caliber rifles (.17, .22 LR): These sit at the quieter end of the firearms spectrum, typically producing peak levels in the low-to-mid 140s dB. They are among the few conventional firearms that can approach, though rarely stay below, the 140 dB impulse limit.
Handguns (9 mm, .40 S&W, .45 ACP): Most common handguns cluster in the 155 to 165 dB range. Shorter barrel lengths mean gas exits the muzzle at higher pressure relative to what a longer rifle barrel would allow, so handguns are often louder than you might expect given their smaller cartridges.
Magnum revolvers (.357 Magnum, .44 Magnum): These tend to sit at the higher end of the handgun range, often 160 to 165 dB or more, because of the high-pressure cartridges and relatively short barrels.
Shotguns (12-gauge): Shotgun blasts typically fall in the 155 to 165 dB range, depending on the load and barrel length. A short-barreled tactical shotgun will be louder than a long-barreled sporting model firing the same shell.
Centerfire rifles (.223/5.56 NATO, .308, .30-06): Rifle cartridges produce peak levels generally between 155 and 170 dB. Larger, higher-velocity cartridges push toward the upper end. The AR-15 platform firing 5.56 NATO typically registers in the upper 150s to low 160s.
Large-caliber and magnum rifles (.300 Win Mag, .338 Lapua): These can reach 170 dB or higher, producing some of the most intense impulse noise among commonly available firearms.

These figures represent peak instantaneous pressure, not the sustained noise levels people are used to hearing about with machinery or concerts. A jackhammer at close range is around 100 to 110 dB of continuous noise, but a gunshot’s peak can be 50 or 60 dB higher than that. Because the decibel scale is logarithmic, every 10 dB increase represents roughly a tenfold jump in sound pressure. A 160 dB gunshot is not “a little louder” than a 130 dB concert; it is orders of magnitude more intense in terms of the pressure hitting your eardrum.

Why Barrel Length Matters More Than You Might Think

One of the most underappreciated factors in gunshot loudness is barrel length. When a bullet travels down a longer barrel, the expanding gases behind it have more time and space to lose pressure before they exit the muzzle. The result is a lower peak sound level. This is why a rifle chambered in 5.56 NATO with a 20-inch barrel is measurably quieter than the same cartridge fired from a 10.5-inch short-barreled rifle. It is also why magnum revolvers with short barrels are disproportionately loud relative to their caliber: the high-pressure gas barely has room to expand before it hits open air.

This relationship also explains why handguns routinely produce peak sound levels comparable to or higher than many rifles, even though rifle cartridges contain far more powder and propel bullets at much higher velocities. The gas pressure at the muzzle of a 4-inch-barrel 9 mm pistol is simply higher than the pressure at the end of a 24-inch-barrel bolt-action rifle. Shooters who switch from a full-size handgun to a compact or subcompact model in the same caliber often notice the gun feels “snappier” and louder, and they are not imagining it.

What Bystanders and People Nearby Actually Experience

The numbers quoted above are generally measured at or near the shooter’s ear position. But anyone nearby is also at risk. A study measuring impulse noise at a bystander location found peak levels ranging from 149 to 167 dB SPL, depending on the firearm.⁵ Even the lower end of that range exceeds the 140 dB safe-impulse limit. For most rifles, the most conservative damage-risk criteria permitted zero unprotected exposures at the bystander position. Shotguns and handguns allowed somewhat more, but “somewhat more” still meant fewer than ten unprotected shots in many cases.

This has real implications for spectators at shooting events, people living near outdoor ranges, and anyone who happens to be in the vicinity when a gun is fired. The idea that standing a few feet behind the shooter puts you in a safe zone is wrong. Sound pressure drops with distance, but the starting levels are so extreme that even at a bystander distance the impulse can cause immediate damage to unprotected ears. Children, whose ear canals are smaller and whose auditory systems are still developing, face a heightened risk in these situations.

Indoor environments make everything worse. Reflective surfaces like concrete walls and ceilings bounce the blast wave back toward the shooter and anyone else in the room. Peak sound levels at indoor ranges have been measured at 156 to 170 dB, and the reverberant buildup can push the effective exposure higher than it would be outdoors for the same firearm and ammunition.⁴

What Suppressors Actually Do

Suppressors, sometimes called silencers, are often misunderstood thanks to movies and television, where a suppressed gunshot sounds like a soft “pfft.” In reality, a suppressor does not make a gun silent. What it does is trap and cool some of the expanding muzzle gas before it escapes, lowering the peak pressure of the blast. The most effective suppressors tested in controlled settings reduced peak sound levels by as much as 35 dB.⁶ That is a substantial reduction on a logarithmic scale, but it still means a 165 dB gunshot drops to around 130 dB, which is about as loud as a jet engine at close range.

That said, suppressors consistently outperformed ear-level hearing protection in direct comparisons. One study found that all tested suppressors offered significantly greater noise reduction than ear-level hearing protectors, usually more than 50% better in terms of the reduction achieved.⁷ The advantage of a suppressor is that it reduces the noise at the source rather than trying to block it at the ear. Combined with hearing protection, a suppressor can bring the effective exposure down to levels that are far more manageable for the auditory system.

Pairing a suppressor with subsonic ammunition produces the greatest overall noise reduction. As mentioned earlier, subsonic rounds eliminate the ballistic shockwave, so a suppressor only needs to handle the muzzle blast.³ This combination is the closest you can get to what people imagine when they think of a “quiet” gun, though even then the shot is audible and well above conversational volume.

Why Standard Hearing Protection Often Falls Short

Most shooters know to wear ear protection, but many underestimate how demanding firearms noise is on protective devices. Foam earplugs and thin earmuffs, which work fine for mowing the lawn or attending a loud concert, are not designed for impulse peaks of 155 to 170 dB. Testing on various protector types found that earplugs alone provided about 16 dB of attenuation against rifle impulse noise, and small-volume earmuffs provided about 17 dB. Neither was sufficient on its own for rifle shooting.⁸

Large-volume earmuffs performed better and were considered adequate as a sole protector for rifles. Pistol and shotgun impulses, which have different spectral characteristics, were fairly well attenuated by either small or large earmuffs. But for large-caliber weapons with heavy low-frequency energy, all types of earmuffs showed attenuation of less than 15 dB, which is insufficient. For those firearms, the recommendation is to double up: earplugs underneath earmuffs.⁸ The combined approach provides meaningfully better protection than either device alone, particularly against the low-frequency energy that single devices struggle to block.

Fit matters enormously, too. A gap between an earmuff cushion and the side of your head, caused by eyeglasses frames or a poor seal, can reduce the effective protection by several decibels at exactly the frequencies that do the most damage. Electronic earmuffs, which amplify quiet sounds while clamping down on loud ones, have become popular among recreational shooters, but their impulse-noise performance varies widely by model and should not be assumed to match their rated noise-reduction values under real shooting conditions.

What Happens to Your Hearing After Exposure

A single gunshot can cause measurable changes in hearing. In one study, exposure to as few as three to four rifle impulses at average peak levels of 154 dB produced significant temporary reductions in otoacoustic emissions, which are faint sounds the inner ear produces in response to stimulation and a sensitive early marker of cochlear stress. The reductions were most pronounced in the frequency range of 1,000 to 4,000 Hz, the range most critical for understanding speech.⁹ These temporary shifts can recover over hours or days, but repeated temporary shifts accumulate into permanent hearing loss over time.

Larger population data reinforces this. A cohort study found that exposure to recreational firearms was associated with elevated hearing thresholds at 3,000 to 6,000 Hz, and the association grew stronger with the number of lifetime shots fired.¹⁰ The damage was worse in older adults and accumulated with age, which fits the pattern of noise-induced hearing loss compounding natural age-related decline. An encouraging finding from the same study was that the association between firearms use and hearing loss was substantially smaller in the more recent cohort, measured about 20 years after the earlier one, coinciding with increased adoption of hearing preservation measures among shooters.

The classic signature of firearms-related hearing loss is a “notch” in hearing sensitivity around 4,000 Hz, sometimes extending to 6,000 Hz. Many people with this pattern can still hear most everyday sounds but struggle to understand speech in noisy environments, miss high-pitched consonants, or develop persistent tinnitus. Because the loss develops gradually, shooters often do not realize anything is wrong until significant damage has already occurred.

Beyond Hearing Damage

High-intensity impulse noise does not only affect the cochlea. Research on blast-wave exposure in animal models has demonstrated significant damage to the vestibular system, which governs balance and spatial orientation. Mice exposed to blast overpressure showed loss of sensory hair cells in the vestibular organs, impaired balance on behavioral tests, and reduced function of the vestibulo-ocular reflex, the mechanism that stabilizes your vision while your head moves.¹¹ Some of this damage persisted for at least a month after a single exposure event and appeared to be permanent.

While the blast pressures used in that research were higher than what a typical shooter experiences at a range, the mechanism is instructive. The inner ear’s vestibular organs and auditory organs share a fluid-filled space, and the same pressure wave that damages hearing hair cells can damage balance hair cells. Dizziness, vertigo, and balance problems are commonly reported among military personnel with blast exposure histories, and some civilian shooters report similar symptoms after years of heavy firearms use, though formal epidemiological data on civilian vestibular outcomes remains thin.

Air Rifles, Starter Pistols, and Other Deceptively Loud Guns

Not every loud gun fires a conventional cartridge. Pellet-powered air rifles, which many people assume are quiet backyard toys, produced peak levels between 117 and 134 dB SPL at the shooter’s ear in controlled testing. All but one of the nine pellet air guns tested exceeded the World Health Organization’s 120 dB peak-level criterion for youth exposure, though none reached the 140 dB firearms threshold.¹² For an adult shooting occasionally, these levels are unlikely to cause lasting damage. For a child or teenager who shoots regularly without hearing protection, the risk is real.

Starter pistols, used at track meets and swimming events, are another underestimated source. Despite firing blanks rather than bullets, .22 and .32 caliber starter pistols produce peak sound pressure levels above 140 dB.¹³ That puts them squarely in the range considered hazardous for unprotected ears. The officials, timers, and athletes standing near a starter pistol at a track event are exposed to impulse noise comparable to what a recreational shooter encounters, and they almost never wear hearing protection. Over an athletic career involving hundreds or thousands of starts, the cumulative exposure adds up.

Nail guns, captive-bolt devices used in livestock operations, and certain industrial tools also produce impulse noise in the 130 to 150 dB range, occasionally higher. The acoustic profile of these devices shares key features with firearms: a very fast pressure rise, a brief duration, and energy concentrated in frequency bands that the human ear is most sensitive to. People who work around these tools daily face impulse-noise risks similar to those of regular shooters, and the same principles of protection apply.

Why Decibel Numbers for Guns Are Hard to Pin Down

If you search online for the decibel level of a specific caliber, you will find tables that list a single number for each cartridge. These tables are useful as rough guides, but the precision they imply is misleading. The same 9 mm cartridge fired from a 5-inch barrel and a 3-inch barrel can differ by several decibels. Ammunition loaded to different pressures by different manufacturers changes the number. The position of the microphone relative to the muzzle matters: measurements taken at the shooter’s ear, one meter to the side, and one meter in front of the muzzle will all return different values. Researchers working to document gunshot acoustics have used specialized microphone arrays with 12 microphones arranged in a semicircle around the muzzle, sampling at 500,000 times per second, to capture the directional variation of a single shot.¹⁴

Even the meter itself introduces complications. Standard sound level meters have different frequency-weighting and time-weighting settings, and different settings applied to the same gunshot can produce readings that differ by 5 dB or more. Testing of suppressor effectiveness, for example, has shown that rankings of which suppressor performs best can shift depending on which sound level meter is used.⁶ This does not mean the measurements are wrong, just that any single number attached to a firearm-and-caliber combination is a snapshot from one specific test condition, not a universal constant. When you see a table that says “9 mm: 160 dB,” treat it as a rough midpoint, not a fixed property of the cartridge.

For practical purposes, the ranges given earlier in this article are more honest than any single-number chart. If you are choosing hearing protection, planning the layout of a shooting range, or evaluating the noise impact on neighbors, assume the worst-case end of the range for your firearm type and plan accordingly. The consequences of underestimating impulse noise are permanent, and they are not forgiving of rounding errors.

1
PubMed Central. Prevention of Noise-Induced Hearing Loss from Recreational Firearms
2
The Journal of the Acoustical Society of America. An introduction to forensic gunshot acoustics
3
PubMed Central. The reduction of gunshot noise and auditory risk through the use of firearm suppressors and low-velocity ammunition
4
PubMed. Assessment of noise exposure for indoor and outdoor firing ranges
5
PubMed. Auditory risk to unprotected bystanders exposed to firearm noise
6
INTER-NOISE and NOISE-CON Congress and Conference Proceedings. Gunshot Suppressors and Sound Level Meters dBZ Peak Performance Tests
7
Otolaryngology–Head and Neck Surgery. Comparison of Muzzle Suppression and Ear‐Level Hearing Protection in Firearm Use
8
PubMed. Physical characteristics of gunfire impulse noise and its attenuation by hearing protectors
9
PubMed. Temporary changes in hearing after exposure to shooting noise
10
PubMed. Cohort difference in the association between use of recreational firearms and hearing loss: findings from the HUNT study
11
PubMed Central. Vestibular Injury After Low-Intensity Blast Exposure
12
PubMed Central. Auditory Risk of Air Rifles
13
International Journal of Audiology. Impulse noise generated by starter pistols
14
ASA Publications (Proceedings of Meetings on Acoustics). Recording anechoic gunshot waveforms of several firearms at 500 kilohertz sampling rate