A-Weighting Calculator

Summary

Enter a frequency and unweighted sound level (dB) to get the A-weighted result in dB(A).

How it works

1. Enter the frequency of the sound in hertz (Hz), from 10 Hz to 20,000 Hz.
2. Enter the unweighted sound pressure level in decibels (dB).
3. The calculator applies the IEC 61672 A-weighting formula to find the correction A(f) at that frequency.
4. The A-weighted level is calculated as: L_A = L_dB + A(f).
5. Results update instantly; adjust either input to compare different tones.
6. The table below shows A-weighting corrections at standard octave-band center frequencies for reference.

Use cases

• Convert a single-frequency noise measurement from dB to dB(A) for regulatory compliance.
• Understand why low-frequency machinery noise (100 Hz) is penalized less than mid-frequency HVAC tones (1 kHz) under A-weighting.
• Verify hand calculations when computing A-weighted octave-band levels before summing them.
• Compare the perceived loudness of different pure tones by checking their A-weighted levels.
• Educate students on the IEC 61672 A-weighting curve and its mathematical basis.
• Quickly look up the A-weighting correction at any non-standard frequency not covered by tabulated data.

Frequently Asked Questions