Sound Intensity Level Calculator

Calculate intensity level, SPL, power, and area together. Switch modes for quick comparisons. See clear results above the form instantly.

Calculator

Choose what you want to compute.
Common value: 1e-12 W/m².
Affects on-screen formatting only.
If given, power P = I × A.
Separate by commas, semicolons, or new lines.
Use RMS acoustic pressure.
Common: 2e-5 Pa.
If blank, compute from ρ and c.
Then Z = ρ · c.

Formula used

Intensity level: L = 10 · log10(I / I₀)

Intensity from level: I = I₀ · 10^(L/10)

From power and area: I = P / A

SPL from pressure: Lp = 20 · log10(prms / p₀)

Intensity from pressure: I = prms² / Z

Impedance option: Z = ρ · c

How to use this calculator

  1. Select the calculation mode you need.
  2. Enter values using your preferred units.
  3. Keep I₀ as 1e-12 W/m² unless required.
  4. For SPL, keep p₀ as 2e-5 Pa.
  5. Press Submit to view results above the form.

Example data table

Case Input Reference Output
Level from intensity I = 1e-6 W/m² I₀ = 1e-12 W/m² L = 60 dB
Intensity from level L = 80 dB I₀ = 1e-12 W/m² I = 1e-4 W/m²
Difference I₁ = 1e-9, I₂ = 1e-6 W/m² I₀ = 1e-12 W/m² ΔL = 30 dB
Combine levels 60 dB + 60 dB I₀ = 1e-12 W/m² ≈ 63.01 dB
SPL from pressure prms = 0.2 Pa, Z = 415 Rayl p₀ = 2e-5 Pa Lp ≈ 80 dB

Examples are idealized, using base-10 logarithms.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.