Sound Intensity Decibel Calculator
Sound level in decibels from intensity or distance.
Enter your values
ⓘ Live results
Results
- Sound level
- 95 dB
- Intensity
- 3.183e-3 W/m²
- Distance
- 5 m
Quick answer
Sound level (dB) = 10 x log10(I / I0), with I0 = 1e-12 W/m^2.
L = 10 log10(I/I0)
How to use the Sound Intensity Decibel Calculator
- 1Enter the acoustic power of the source and the listening distance.
- 2The calculator spreads the power over a sphere to get intensity, then converts to decibels.
- 3Compare the result against common reference levels (60 dB conversation, 120 dB pain threshold).
Worked example
Using the values the calculator loads with:
Inputs
- Source power1 W
- Distance from source5 m
Results
- Sound level95 dB
- Intensity3.183e-3 W/m²
- Distance5 m
Frequently asked questions
Why does doubling distance drop the level by 6 dB?
Intensity falls with the square of distance, and each doubling of intensity is about 3 dB, so distance doubling is about 6 dB.
Is this the same as loudness?
Decibels measure physical intensity; perceived loudness also depends on frequency and human hearing sensitivity.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.