Noise - Maximum Daily Dose Level

Calculate daily noise exposure dose and convert to 8-hr Time-Weighted Average (TWA). When exposed to different noise levels throughout the day, this tool computes the cumulative daily dose as a percentage and the corresponding TWA in dB(A). According to NIOSH guidelines, the daily dose should not exceed 100%.

Noise Dose Calculation

When exposed to different noise levels throughout a working day, the daily dose can be calculated using:

D = (te₁/td₁ + te₂/td₂ + ... + teₙ/tdₙ) × 100%

where:

  • D = daily noise exposure (%)
  • te = exposure time at a specified noise level (min)
  • td = maximum duration time at specified noise level (min)

The Time-Weighted Average (TWA) for an 8-hour shift is then calculated as:

TWA = 10 log(D/100) + 85

According to NIOSH, the daily dose level should not exceed 100%.

Calculator

Inputs

Results

Daily Noise Dose-- %
8-hr Time-Weighted Average (TWA)-- dB(A)
Daily Noise Dose (%)8-hr TWA (dB(A))
2078
3079.8
4081
5082
6082.8
7083.5
8084
9084.5
10085
20088
40091
60092.8
80094
100095
150096.8
200098
4000101
6000102.8
8000104
10000105
20000108
40000111
60000112.8
80000114
100000115
150000116.8
200000118
400000121
600000122.8
800000124
1000000125
2000000128
4000000131
6000000132.8
8000000134
10000000135
20000000138
Noise - Maximum Daily Dose Level | MEPKit Engineering Tools | MEPKit