Noise Exposure Limit Calculator
Estimate how long you can safely remain in a noisy environment before exceeding OSHA's permissible exposure limit. Enter the A-weighted sound level in decibels to see the recommended maximum duration.
Consult safety professionals for workplace hearing protection requirements.
Examples
- 90 dBA ⇒ 8 h
- 95 dBA ⇒ 4 h
- 100 dBA ⇒ 2 h
FAQ
Why limit noise exposure?
Prolonged loud noise damages the tiny hair cells in the inner ear, leading to permanent hearing loss or tinnitus.
What standard does this follow?
The calculator uses OSHA's 29 CFR 1910.95 standard with a 5 dB exchange rate and 90 dBA permissible exposure limit.
Do earplugs extend the limit?
Yes. Subtract the effective noise reduction rating (NRR) from the measured level and enter the reduced level to see the new limit.
Can I use this for impulsive noises?
No. Impulsive or impact noises require specialized analysis and may have much lower allowable exposure durations.
What happens below 90 dBA?
The formula produces durations longer than 8 hours. Treat any value above a normal work shift as compliant but still consider hearing conservation practices.
Additional Information
- OSHA's permissible exposure limit is 90 dBA for 8 hours with a 5 dB exchange rate, meaning every 5 dB increase halves the safe time.
- Results above 8 hours indicate that the exposure is within an 8-hour work shift limit.
- For 85 dBA, many organizations recommend a more conservative 16-hour limit following the same exchange rate.
- Combine this tool with a noise dosimeter or sound level meter to monitor actual exposures during the day.
Extend your hearing conservation toolkit
Read the decibel article for the ISO-backed rules on references, weighting, and 10/20 log usage, then dive into the sound pressure level and sound intensity level explainers before comparing directional coverage with the steradian overview and phase alignment with the radian guide when acoustic and vibration teams coordinate mitigation strategies.