Internal Noise Calculator

The internal noise calculator can be used to estimate internal noise levels in a room from a measured external noise level. The calculation is based on BS EN 12354-3 – Estimation of acoustic performance of buildings from the performance of elements, and accounts for transmission losses of walls, windows and doors.

The following formula is used to estimate the internal noise level:

L2 = L1 – R + 10log(S) – 10log(A)


L2 = Sound pressure level in receiving room (dB)

L1 = Sound pressure level 1m from the facade (dB)

R = Sound reduction index (dB)

S = Element area (m2)

A = Total absorption equivalent area in receiving room (m2)

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Please note that this or any other calculators on the tools room are for information only. WKC Group has endeavoured to ensure that the information presented here is accurate and that the calculations are correct, but will not accept responsibility for any consequential damages, faults or human errors that may arise from the use of formulas, inventories and values.