About the Sound Intensity Calculator
Sound intensity level in decibels from intensity or power, and how it falls with distance.
Also known as: sound level, db from intensity, sound power to db, inverse square sound.
How to use this calculator
- Enter sound intensity, distance from source, new distance.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
L = 10·log₁₀(I / 10⁻¹²) · I ∝ 1/r²
Worked example
Using the values pre-filled in the calculator above:
- Sound intensity = 0.001 W/m²
- Distance from source = 1 m
- New distance = 4 m
the calculator returns:
- Sound level: 90 dB
- Intensity at new distance: 0.0000625 W/m²
- Level at new distance: 77.96 dB
- Change: -12.04 dB