How to use the sound power and intensity calculator
Compute intensity at distance from a source power. Enter source power, distance in the fields above; the intensity, level are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “how loud is a speaker”, “source power spreading”, “sound intensity”, “calculate sound power and intensity”, “find intensity”.
Formula
Variables
- P — Source power (W)
- r — Distance (m)
Worked example
With source power = 0.5 W, distance = 3 m, the calculator gives intensity ≈ 0.00442097 W/m²; level ≈ 96.45518 dB.
Frequently asked questions
What is the sound power and intensity calculator used for?
Compute intensity at distance from a source power. It helps with questions such as “how loud is a speaker”, “source power spreading”, “sound intensity”.
What is the formula for the sound power and intensity calculation?
Intensity (W/m²) = P / (4 × π × r × r). Level (dB) = 10 × log10([Intensity] / 1e-12). Here P is source power (W), r is distance (m).
What inputs do I need for the sound power and intensity calculator?
You need source power in W, distance in m. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the sound power and intensity calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the sound power and intensity result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.