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Free Decibel Meter

100 Decibels — How Loud Is It?

Dangerous

100 dB is about as loud as chainsaw. A chainsaw, a jackhammer at 15 meters, or crowd noise inside a sports arena all commonly reach 100 dB. Under NIOSH's exposure model, safe unprotected exposure at this level drops to about 15 minutes a day — a small fraction of the 8 hours allowed at 85 dB.

What does 100 dB sound like?

  • 100 dB — Chainsaw
  • 100 dB — Jackhammer, 15 m away
  • 100 dB — Sports arena crowd noise

Safe exposure time at 100 dB

Under NIOSH's Recommended Exposure Limit (85 dB, 3 dB exchange rate), safe unprotected exposure at 100 dB is about 15 minutes per day. Under OSHA's legal Permissible Exposure Limit (90 dB, 5 dB exchange rate), it is about 2.0 hours per day.

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    Frequently asked questions

    How long is 100 dB ok?
    Under NIOSH's 3 dB exchange-rate model, safe unprotected exposure at 100 dB LAeq drops to about 15 minutes per day — a small fraction of the 8 hours allowed at 85 dB.
    What produces 100 dB?
    A chainsaw, a jackhammer at 15 meters, and crowd noise inside a sports arena all commonly reach around 100 dB.
    Can 100 dB damage hearing quickly?
    Yes — even short unprotected exposure near 100 dB can contribute to permanent hearing damage, especially with repeated exposures over time, per NIOSH's exposure-limit model.

    Sources