All toolsAdd Decibels Calculator

Sound levels add as energy, not ordinary numbers.

Combine independent sound levels measured with compatible metrics and see their logarithmic total.

Independent sound levels

Enter levels measured with the same weighting and metric. The calculator combines their sound energies instead of adding the decibel numbers directly.

Sound level 1
Sound level 2
How it works

Convert, add, convert back

Each decibel level is converted to a linear energy ratio, the ratios are added and the total is converted back to decibels.

Quick check

Equal levels add 3 dB

Two independent 80 dB sources combine to approximately 83 dB, not 160 dB. Read why the decibel scale is logarithmic.

Important limits

Match the metrics

Do not combine incompatible averages, peaks or weightings as if they described the same quantity. Coherent phase-related signals need a different method. See the OSHA technical guidance.