Convert a pure-tone or measured octave-band sound-pressure level to an A-weighted estimate with explicit frequency and scope limits.
dB to dBA Formula and Scope
A-weighting is frequency dependent. For a pure tone, the calculator uses L_A = L_Z + A(f). For several octave bands, it applies the correction to each band and then performs a logarithmic energy sum: L_A,total = 10 log10(Σ 10^((L_i + A_i)/10)).
The weighting response follows the frequency-response equations in IEC 61672. A single broadband dB or dBZ reading cannot be reliably converted to dBA without spectral data. Use calibrated instrumentation and measured octave bands for occupational or regulatory work.
Important Safety Limits
This tool changes frequency weighting only. It does not calculate exposure duration, noise dose, hearing risk, or regulatory compliance. It also does not convert audiometric dB HL thresholds. For workplace decisions, use a competent noise assessment and the standard required in the applicable jurisdiction.
Primary references: OSHA Technical Manual, Occupational Noise Exposure and NIOSH Noise and Hearing Loss.
