Noise Exposure Calculator (TWA) | Free OSHA

Calculate your 8-hour Time-Weighted Average noise exposure. Compare to OSHA PEL (90 dBA) and Action Level (85 dBA). Get hearing protection recommendations.

Calculate accurate OSHA penalty risks and safety ROI instantly. Get precise estimates based on 2026 adjustment data to prevent financial loss and justify your safety budget. Free, offline-ready analysis tool.

What is this tool?

The Noise Exposure Calculator computes the 8-hour Time-Weighted Average (TWA) for workers exposed to varying noise levels throughout a shift. Using OSHA's exchange rate formula, it determines if exposure exceeds the Permissible Exposure Limit (90 dBA) or triggers the Action Level (85 dBA), and recommends appropriate hearing protection.

OSHA requirement

29 CFR 1910.95 (General Industry) and 1926.52 (Construction) set the PEL at 90 dBA TWA and require a Hearing Conservation Program when exposures reach or exceed the 85 dBA Action Level. This includes audiometric testing, hearing protection, and training. Construction employers must provide hearing protection at 90 dBA per 1926.52(b).

How to use it

Add noise exposure entries by selecting common construction noise sources (or entering custom dBA levels) and the duration for each. The calculator computes the cumulative dose and TWA, compares against OSHA limits, and recommends hearing protection type (plugs, muffs, or dual) with effective NRR calculations.

How to Calculate Noise Exposure TWA

1. Add noise sources: Select common construction noise sources (jackhammer, grinder, saw, etc.) or enter custom dBA levels.
2. Set exposure durations: Enter the number of hours per day each noise source is active during the shift.
3. Review TWA results: See the calculated 8-hour TWA compared to the OSHA PEL (90 dBA) and Action Level (85 dBA).
4. Get PPE recommendations: Receive hearing protection recommendations (plugs, muffs, or dual) with effective NRR calculations.

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