Work out noise exposure level (lex) instantly with clear inputs, formula shown and shareable results.
Daily noise exposure normalised to eight hours uses the equal-energy three decibel rule: LEX,8h = L + 10 log10(T/8). Halving the exposure time therefore reduces the daily level by three decibels. Exposure points express the same thing on a linear scale where 100 points equals 85 dB, which makes combining several tasks a matter of addition.
Daily exposure level
LEX,8h = L + 10 log10(T / 8)
Exposure points
Points = 100 x 10^((LEX - 85) / 10)
Preliminary estimate only. Noise risk assessment must be carried out by a competent person to the noise regulations in force.
LEX,8h = L + 10 log10(T / 8). Daily noise exposure normalised to eight hours uses the equal-energy three decibel rule: LEX,8h = L + 10 log10(T/8).
Decibels cannot be added arithmetically. Points can, so the contributions of several noisy tasks in a shift are simply summed and compared with the 100 point action value.
This calculator takes 2 inputs: A-weighted sound level, Exposure duration. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.