Hearing Protection NRR Calculator

Effective noise reduction from protection type and fit.

Firearm noise level (dB)

Primary NRR rating

Secondary NRR rating

Suppressor reduction (dB)

Shots per session

Tab to move between fields

Noise at ear (dB)

152

Total reduction (dB)13

Primary effective NRR (dB)13

Margin to 140 dB limit-12

Session Leq (dB)114.2

Meets OSHA limit (1=yes)0

Risk LevelExtreme - hearing damage likely

How to Use This Calculator

Enter the Firearm Noise Level in dB (pistol ~160 dB, rifle ~165 dB, magnum ~170 dB).
Set the Primary NRR rating of your hearing protection.
Optionally add a Secondary NRR for dual-protection (plugs under muffs) and Suppressor Reduction in dB.
Enter Shots per Session for a session noise exposure estimate.
Review Noise at Ear (dB), Total Reduction, and whether the setup meets the OSHA 140 dB impulse limit.

How the result changes with Firearm noise level (dB)

Firearm noise level (dB): Peak sound level of the firearm (pistol ~160 dB, rifle ~165 dB, magnum ~170 dB).
Primary NRR rating: Noise Reduction Rating of primary hearing protection (ear muffs or plugs).
Secondary NRR rating: NRR of second device for dual protection (set to 0 if not using dual). E.g. plugs under muffs.
Suppressor reduction (dB): Decibel reduction from a suppressor/silencer (typically 25-35 dB). Set to 0 if none.
Shots per session: Number of rounds fired in a typical range session.

Noise at ear (dB): Effective sound level reaching your ear after all protection.
Total reduction (dB): Combined noise reduction from all protection devices.
Primary effective NRR (dB): OSHA-derated effective reduction from primary hearing protection.
Margin to 140 dB limit: Decibels below the 140 dB OSHA impulse noise limit (positive = safe).
Session Leq (dB): Equivalent continuous noise level for the session.
Meets OSHA limit (1=yes): Whether effective noise is at or below 140 dB impulse limit.

Identify Input Parameters
4 parameters
Firearm noise level (dB) = 165, Primary NRR rating = 33, Secondary NRR rating = 0, Suppressor reduction (dB) = 0 = 5 input(s) provided
Calculate Noise at ear
Noise at ear = firearmNoiseDb - totalWithSuppressor
152 = 152
Calculate Total reduction
Total reduction = totalEffectiveReduction + suppressorReductionDb
13 = 13
Calculate Primary effective NRR
13 = 13