Calculate how sound or signal strength decreases with distance.
Propagation Parameters
dB
m
m
Calculation Results
Enter levels and distances
About this calculator
Quick Reference
L₁Initial Level (at d₁)
L₂Final Level (at d₂)
d₁Reference distance
d₂Target distance
6 dB RuleDoubling distance = -6 dB
Overview
Distance attenuation describes how the intensity or level of a signal decreases as it spreads out from a source. In an open field (free field), sound level follows the inverse square law.
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Pro Tips
Doubling the distance from a point source reduces the sound level by 6 dB.
The formula assumes a 'point source' in an 'open field' without reflections.
Indoor environments will have less attenuation due to sound reflecting off walls.
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Fun Facts
"The inverse square law applies to many forms of radiation, including light, radio waves, and gravity."
"The loudest animal, the blue whale, can be heard across entire oceans because water attenuates sound much less than air does."
